An off-by-one heap-based buffer overflow was found in the vsysloginternal function of the glibc library. This function is called by the syslog and vsyslog functions. This issue occurs when these functions are called with a message bigger than INTMAX bytes, leading to an incorrect calculation of the buffer size to store the message, resulting in an application crash. This issue affects glibc 2.37 and newer.

A heap-based buffer overflow was found in the vsysloginternal function of the glibc library. This function is called by the syslog and vsyslog functions. This issue occurs when the openlog function was not called, or called with the ident argument set to NULL, and the program name (the basename of argv[0]) is bigger than 1024 bytes, resulting in an application crash or local privilege escalation. This issue affects glibc 2.36 and newer.

A buffer overflow was discovered in the GNU C Library's dynamic loader ld.so while processing the GLIBCTUNABLES environment variable. This issue could allow a local attacker to use maliciously crafted GLIBCTUNABLES environment variables when launching binaries with SUID permission to execute code with elevated privileges.

GNU glibc is vulnerable to a denial of service, caused by a buffer over-read in iconv feature. By sending a specially-crafted request, a remote attacker could exploit this vulnerability to cause a SIGSEGV.

A flaw was found in glibc. The realpath function may sometimes return a unexpected value, potentially leading to disclosure of sensitive data.

Last updated 24 July 2024

Last updated 24 July 2024

DISPUTED In iconvdata/iso-2022-jp-3.c in the GNU C Library (aka glibc) 2.34, remote attackers can force iconv() to emit a spurious '\0' character via crafted ISO-2022-JP-3 data that is accompanied by an internal state reset. This may affect data integrity in certain iconv() use cases. NOTE: the vendor states "the bug cannot be invoked through user input and requires iconv to be invoked with a NULL inbuf, which ought to require a separate application bug to do so unintentionally. Hence there's no security impact to the bug."

The string component in the GNU C Library (aka glibc or libc6) through 2.28, when running on the x32 architecture, incorrectly attempts to use a 64-bit register for sizet in assembly codes, which can lead to a segmentation fault or possibly unspecified other impact, as demonstrated by a crash in memmoveavxunalignederms in sysdeps/x8664/multiarch/memmove-vec-unaligned-erms.S during a memcpy.

Last updated 24 July 2024

Integer overflow in the strxfrm function in the GNU C Library (aka glibc or libc6) before 2.21 allows context-dependent attackers to cause a denial of service (crash) or possibly execute arbitrary code via a long string, which triggers a stack-based buffer overflow.

Integer overflow in the IOwstroverflow function in libio/wstrops.c ...

ld.so in the GNU C Library (aka glibc or libc6) before 2.11.3, and 2.12.x before 2.12.2, does not properly restrict use of the LDAUDIT environment variable to reference dynamic shared objects (DSOs) as audit objects, which allows local users to gain privileges by leveraging an unsafe DSO located in a trusted library directory, as demonstrated by libpcprofile.so.

nis/nssnis/nis-pwd.c in the GNU C Library (aka glibc or libc6) 2.7 and Embedded GLIBC (EGLIBC) 2.10.2 adds information from the passwd.adjunct.byname map to entries in the passwd map, which allows remote attackers to obtain the encrypted passwords of NIS accounts by calling the getpwnam function.

It was reported [1] that getnetbyname function in glibc 2.21 in earlier will enter an infinite loop if the DNS backend is activated in the system Name Service Switch configuration, and the DNS resolver receives a positive answer while processing the network name.

Upstream commit that fixes this issue: https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=11e3417af6e354f1942c68a271ae51e892b2814d

[1]: https://sourceware.org/bugzilla/showbug.cgi?id=17630

Off-by-one error in the gconvtranslitfind function in gconvtrans.c in GNU C Library (aka glibc) allows context-dependent attackers to cause a denial of service (crash) or execute arbitrary code via vectors related to the CHARSET environment variable and gconv transliteration modules.

A stack-based buffer overflow was found in libresolv when invoked from nssdns, allowing specially crafted DNS responses to seize control of EIP in the DNS client.

The buffer overflow occurs in the functions senddg (send datagram) and sendvc (send TCP) for the NSS module libnssdns.so.2 when calling getaddrinfo with AFUNSPEC family, or in some cases AFINET6 family. The use of AFUNSPEC (or AFINET6 in some cases) triggers the low-level resolver code to send out two parallel queries for A and AAAA. A mismanagement of the buffers used for those queries could result in the response of a query writing beyond the alloca allocated buffer created by resnquery.

It was discovered that the nssfiles backend for the Name Service Switch in glibc would return incorrect data to applications or corrupt the heap (depending on adjacent heap contents), potentially resulting in arbitrary code execution.

Stack-based buffer overflow in the nssdns implementation of the getnetbyname function in GNU C Library (aka glibc) before 2.24 allows context-dependent attackers to cause a denial of service (stack consumption and application crash) via a long name.

ptchown in the glibc package before 2.19-18+deb8u4 on Debian jessie; the elibc package before 2.15-0ubuntu10.14 on Ubuntu 12.04 LTS and before 2.19-0ubuntu6.8 on Ubuntu 14.04 LTS; and the glibc package before 2.21-0ubuntu4.2 on Ubuntu 15.10 and before 2.23-0ubuntu1 on Ubuntu 16.04 LTS and 16.10 lacks a namespace check associated with file-descriptor passing, which allows local users to capture keystrokes and spoof data, and possibly gain privileges, via pts read and write operations, related to debian/sysdeps/linux.mk. NOTE: this is not considered a vulnerability in the upstream GNU C Library because the upstream documentation has a clear security recommendation against the --enable-ptchown option.

A flaw was found in the way memory was being allocated on the stack for user space binaries. If heap and stack memory regions were adjacent to each other, an attacker could use this flaw to jump over the heap/stack gap, cause controlled memory corruption on process stack or heap, and thus increase their privileges on the system.

This is a tracking bug for the glibc part of the mitigation.

DISPUTED The xdrbytes and xdrstring functions in the GNU C Library (aka glibc or libc6) 2.25 mishandle failures of buffer deserialization, which allows remote attackers to cause a denial of service (virtual memory allocation, or memory consumption if an overcommit setting is not used) via a crafted UDP packet to port 111, a related issue to CVE-2017-8779. NOTE: [Information provided from upstream and references]

In the GNU C Library (aka glibc or libc6) through 2.29, checkdstlimitscalcpos1 in posix/regexec.c has Uncontrolled Recursion, as demonstrated by '(\227|)(\\1\\1|t1|\\\2537)+' in grep.

GNU C Library is vulnerable to a stack-based buffer overflow, caused by not handling non-normal x86 long double numbers gracefully for printf family functions. By sending a specially crafted value to the functions, a local attacker could overflow a buffer and execute arbitrary code on the system or cause the application to crash.

An issue was discovered in the GNU C Library (glibc) 2.36. When the syslog function is passed a crafted input string larger than 1024 bytes, it reads uninitialized memory from the heap and prints it to the target log file, potentially revealing a portion of the contents of the heap.

It was discovered that the nssfiles backend for the Name Service Switch in glibc would return incorrect data to applications or corrupt the heap (depending on adjacent heap contents), potentially resulting in arbitrary code execution.

A buffer underflow in realpath() in glibc when getcwd() returns relative path or unreachable path (i.e. not starting with '/') was found that can allow privilege escalation under certain conditions.

Reference:

http://www.openwall.com/lists/oss-security/2018/01/11/5

A flaw was found in the way memory was being allocated on the stack for user space binaries. If heap and stack memory regions were adjacent to each other, an attacker could use this flaw to jump over the heap/stack gap, cause controlled memory corruption on process stack or heap, and thus increase their privileges on the system.

This is a tracking bug for the glibc part of the mitigation.