glibc vulnerabilities

A heap-based buffer overflow was found in the __vsyslog_internal function of the glibc library. This issue occurs when the syslog and vsyslog functions are called with a message larger than INT_MAX bytes, leading to an incorrect buffer size calculation and application crash.

The res_query function in libresolv in glibc before version 2.25 has a vulnerability that allows remote attackers to cause a denial of service through a NULL pointer dereference, leading to process crashes.

glibc contains a vulnerability that allows specially crafted LD_LIBRARY_PATH values to manipulate the heap/stack, potentially resulting in arbitrary code execution. This affects glibc 2.25 and earlier.

The calloc function in the glibc package in Red Hat Enterprise Linux (RHEL) 6.7 and 7.2 does not properly initialize memory areas, which might allow context-dependent attackers to cause a denial of service (hang or crash) via unspecified vectors.

In glibc versions before 2.19-18+deb8u4 on Debian jessie and before 2.15-0ubuntu10.14 on Ubuntu 12.04 LTS, 2.19-0ubuntu6.8 on Ubuntu 14.04 LTS, 2.21-0ubuntu4.2 on Ubuntu 15.10, and 2.23-0ubuntu1 on Ubuntu 16.04 LTS and 16.10, there is a lack of namespace check associated with file-descriptor passing. This allows local users to capture keystrokes and spoof data, potentially gaining privileges.

CVE-2015-0235 involves a heap-based buffer overflow in the __nss_hostname_digits_dots function in glibc in versions 2.2 and other 2.x versions before 2.18. This allows attackers to execute arbitrary code via the gethostbyname or gethostbyname2 functions.

The posix_spawn_file_actions_addopen function in glibc before 2.20 does not copy its path argument in accordance with the POSIX specification, allowing context-dependent attackers to trigger use-after-free vulnerabilities.

A flaw in glibc may cause the gaih_inet function to use freed memory in uncommon situations, leading to an application crash. This issue is only exploitable when getaddrinfo is called and the hosts database in /etc/nsswitch.conf is configured with SUCCESS=.

In glibc 2.15, a bug was introduced in the nscd daemon that causes a null pointer dereference when a not-found netgroup response is not added to the cache. This leads to a crash of nscd.

The deprecated compatibility function clnt_create in the sunrpc module of the GNU C Library (glibc) through 2.34 copies its hostname argument on the stack without validating its length. This may result in a buffer overflow, potentially leading to a denial of service or, if an application is not built with a stack protector enabled, arbitrary code execution.

The deprecated compatibility function svcunix_create in the sunrpc module of the GNU C Library (aka glibc) through 2.34 copies its path argument on the stack without validating its length, which may result in a buffer overflow, potentially resulting in a denial of service or (if an application is not built with a stack protector enabled) arbitrary code execution.

The mq_notify function in the GNU C Library (glibc) versions 2.32 and 2.33 has a use-after-free. It may use the notification thread attributes object (passed through its struct sigevent parameter) after it has been freed by the caller, leading to a denial of service (application crash) or possibly unspecified other impact.

The manual/search.texi documentation in the GNU C Library (glibc) before 2.2 lacks a statement about the unspecified tdelete return value upon deletion of a tree's root. This may allow attackers to access a dangling pointer in an application whose developer was unaware of a documentation update from 1999.

In the GNU C Library (aka glibc or libc6) through 2.29, proceed_next_node in posix/regexec.c has a heap-based buffer over-read via an attempted case-insensitive regular-expression match.

The iconv program in the GNU C Library (aka glibc or libc6) 2.31 and earlier, when invoked with multiple suffixes in the destination encoding (TRANSLATE or IGNORE) along with the -c option, enters an infinite loop when processing invalid multi-byte input sequences, leading to a denial of service.

A stack-based buffer overflow in the dynamic loader (ld.so) of the GNU C Library (glibc) versions 2.14 through 2.44 allows a local attacker to crash or corrupt the memory of setuid/setgid (AT_SECURE) programs. When such a program's DT_RPATH or DT_RUNPATH begins with $ORIGIN and is followed by NUL or '/', the loader both reads past the end of the path buffer and writes past the end of a stack-allocated internal buffer. The corrupted loader stack can lead to a loader crash (denial of service) and limited disclosure of process memory.

A time-of-check to time-of-use (TOCTOU) race condition in the dynamic loader (ld.so) of the GNU C Library (glibc) versions 2.14 through 2.44 allows a local attacker to escalate privileges. When expanding $ORIGIN in DT_RPATH for setuid/setgid (AT_SECURE) programs, glibc validates the lexically normalized search path against trusted directories but then opens the raw, un-normalized path. On systems where the Linux fs.protected_hardlinks sysctl is disabled, a local attacker who hard-links such a program into an attacker-controlled directory and wins a race to replace an intermediate path component with a symbolic link can direct the loader outside the trusted directory, causing it to load an attacker-controlled shared object and execute arbitrary code with the elevated privileges of the program.

When expanding paths that begin with a tilde (~) followed by a username, the internal parse_tilde function extracts the username to determine the user's home directory. The implementation allocates memory for this username directly on the stack using the strndupa macro. Because the size of this allocation was determined by the length of the user-supplied input without any bounds checks, passing an excessively long username (e.g., thousands of characters) forces the thread to exhaust its stack space, potentially leading to a stack clash.

A use-after-free flaw has been found in glibc's getaddrinfo function. In an extremely rare scenario where an NSS module implements only specific hooks and the query meets certain conditions, an application crash may occur.

A flaw was found in glibc. An off-by-one buffer overflow and underflow in getcwd() may lead to memory corruption when the size of the buffer is exactly 1. A local attacker who can control the input buffer and size passed to getcwd() in a setuid program could use this flaw to potentially execute arbitrary code and escalate their privileges on the system.

A flaw was found in glibc. The realpath() function can mistakenly return an unexpected value, potentially leading to information leakage and disclosure of sensitive data.

In iconvdata/iso-2022-jp-3.c in the GNU C Library (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. 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.

In librt in the GNU C Library (glibc) through 2.34, sysdeps/unix/sysv/linux/mq_notify.c mishandles certain NOTIFY_REMOVED data, leading to a NULL pointer dereference. This vulnerability was introduced as a side effect of the CVE-2021-33574 fix.

The iconv function in the GNU C Library (glibc) 2.32 and earlier, when processing invalid multi-byte input sequences in IBM1364, IBM1371, IBM1388, IBM1390, and IBM1399 encodings, fails to advance the input state, which could lead to an infinite loop in applications, resulting in a denial of service, a different vulnerability from CVE-2016-10228.

The nameserver caching daemon (nscd) in the GNU C Library (aka glibc or libc6) 2.29 through 2.33, when processing a request for netgroup lookup, may crash due to a double-free, potentially resulting in degraded service or Denial of Service on the local system. This is related to netgroupcache.c.

The iconv function in the GNU C Library (aka glibc or libc6) 2.32 and earlier, when processing invalid input sequences in the ISO-2022-JP-3 encoding, fails an assertion in the code path and aborts the program, potentially resulting in a denial of service.

The iconv feature in the GNU C Library (aka glibc or libc6) through 2.32, when processing invalid multi-byte input sequences in the EUC-KR encoding, may have a buffer over-read.

sysdeps/i386/ldbl2mpn.c in the GNU C Library (aka glibc or libc6) before 2.23 on x86 targets has a stack-based buffer overflow if the input to any of the printf family of functions is an 80-bit long double with a non-canonical bit pattern.

The iconv function in the GNU C Library (glibc) 2.30 to 2.32, when converting UCS4 text containing an irreversible character, fails an assertion in the code path and aborts the program, potentially resulting in a denial of service.

A use-after-free vulnerability introduced in glibc upstream version 2.14 was found in the way the tilde expansion was carried out. Directory paths containing an initial tilde followed by a valid username were affected by this issue. A local attacker could exploit this flaw by creating a specially crafted path that, when processed by the glob function, would potentially lead to arbitrary code execution. This was fixed in version 2.32.

An out-of-bounds write vulnerability was found in glibc before 2.31 when handling signal trampolines on PowerPC. The backtrace function did not properly check the array bounds when storing the frame address, resulting in a denial of service or potential code execution. The highest threat from this vulnerability is to system availability.

The GNU C Library (glibc) before 2.32 could overflow an on-stack buffer during range reduction if an input to an 80-bit long double function contains a non-canonical bit pattern, as seen when passing a 0x5d414141414141410000 value to sinl on x86 targets. This is related to sysdeps/ieee754/ldbl-96/e_rem_pio2l.c.

On x86-64, GNU C Library (glibc) before 2.31 fails to ignore the LD_PREFER_MAP_32BIT_EXEC environment variable during program execution after a security transition, allowing local attackers to restrict mapping addresses for loaded libraries and bypass ASLR for setuid programs.

GNU Libc current is affected by: Re-mapping current loaded library with malicious ELF file. The impact is: In worst case attacker may evaluate privileges. The component is: libld. The attack vector is: Attacker sends 2 ELF files to victim and asks to run ldd on it. ldd execute code. NOTE: Upstream comments indicate "this is being treated as a non-security bug and no real threat."

In the GNU C Library (glibc) through 2.29, the memcmp function for the x32 architecture can incorrectly return zero (indicating that the inputs are equal) because the RDX most significant bit is mishandled. This can lead to incorrect comparison results.

In the GNU C Library (glibc) through 2.28, the getaddrinfo function would successfully parse a string that contained an IPv4 address followed by whitespace and arbitrary characters, which could lead applications to incorrectly assume that it had parsed a valid string, without the possibility of embedded HTTP headers or other potentially dangerous substrings.

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 size_t in assembly codes, which can lead to a segmentation fault or possibly unspecified other impact, as demonstrated by a crash in __memmove_avx_unaligned_erms in sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S during a memcpy.

glibc2 does not properly clear the LD_DEBUG_OUTPUT and LD_DEBUG environmental variables when a program is spawned from a setuid program, which could allow local users to overwrite files via a symlink attack.

The resolver in glibc 2.1.3 uses predictable IDs, allowing a local attacker to spoof DNS query results.