GNU Glibc

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 LD_AUDIT 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.

The unsetenv function in glibc 2.1.1 does not properly unset an environmental variable if the variable is provided twice to a program, which could allow local users to execute arbitrary commands in setuid programs by specifying their own duplicate environmental variables such as LD_PRELOAD or LD_LIBRARY_PATH.

The get_contents function in nss_files/files-XXX.c in the Name Service Switch (NSS) in GNU C Library (aka glibc or libc6) before 2.20 might allow local users to cause a denial of service (heap corruption) or gain privileges via a long line in the NSS files database.

The encode_name macro in misc/mntent_r.c in the GNU C Library (aka glibc or libc6) 2.11.1 and earlier, as used by ncpmount and mount.cifs, does not properly handle newline characters in mountpoint names, which allows local users to cause a denial of service (mtab corruption), or possibly modify mount options and gain privileges, via a crafted mount request.

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.

A buffer overflow in glibc 2.5 (released on September 29, 2006) and can be triggered through the LD_LIBRARY_PATH environment variable. Please note that many versions of glibc are not vulnerable to this issue if patched for CVE-2017-1000366.

An out-of-bounds write vulnerability was found in glibc before 2.31 when handling signal trampolines on PowerPC. Specifically, 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.

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.

elf/dl-load.c in ld.so in the GNU C Library (aka glibc or libc6) through 2.11.2, and 2.12.x through 2.12.1, does not properly handle a value of $ORIGIN for the LD_AUDIT environment variable, which allows local users to gain privileges via a crafted dynamic shared object (DSO) located in an arbitrary directory.

Multiple untrusted search path vulnerabilities in elf/dl-object.c in certain modified versions of the GNU C Library (aka glibc or libc6), including glibc-2.5-49.el5_5.6 and glibc-2.12-1.7.el6_0.3 in Red Hat Enterprise Linux, allow local users to gain privileges via a crafted dynamic shared object (DSO) in a subdirectory of the current working directory during execution of a (1) setuid or (2) setgid program that has $ORIGIN in (a) RPATH or (b) RUNPATH within the program itself or a referenced library. NOTE: this issue exists because of an incorrect fix for CVE-2010-3847.

ldd in the GNU C Library (aka glibc or libc6) 2.13 and earlier allows local users to gain privileges via a Trojan horse executable file linked with a modified loader that omits certain LD_TRACE_LOADED_OBJECTS checks. NOTE: the GNU C Library vendor states "This is just nonsense. There are a gazillion other ways to introduce code if people are downloading arbitrary binaries and install them in appropriate directories or set LD_LIBRARY_PATH etc.

Integer signedness error in Glibc before 2.13 and eglibc before 2.13, when using Supplemental Streaming SIMD Extensions 3 (SSSE3) optimization, allows context-dependent attackers to execute arbitrary code via a negative length parameter to (1) memcpy-ssse3-rep.S, (2) memcpy-ssse3.S, or (3) memset-sse2.S in sysdeps/i386/i686/multiarch/, which triggers an out-of-bounds read, as demonstrated using the memcpy function.

Integer overflow in the __tzfile_read function in glibc before 2.15 allows context-dependent attackers to cause a denial of service (crash) and possibly execute arbitrary code via a crafted timezone (TZ) file, as demonstrated using vsftpd.

Buffer overflow in the gethostbyname_r and other unspecified NSS functions in the GNU C Library (aka glibc or libc6) before 2.22 allows context-dependent attackers to cause a denial of service (crash) or execute arbitrary code via a crafted DNS response, which triggers a call with a misaligned buffer.

sysdeps/posix/readdir_r.c in the GNU C Library (aka glibc or libc6) 2.18 and earlier allows context-dependent attackers to cause a denial of service (out-of-bounds write and crash) or possibly execute arbitrary code via a crafted (1) NTFS or (2) CIFS image.

The vfprintf function in stdio-common/vfprintf.c in GNU C Library (aka glibc) 2.5, 2.12, and probably other versions does not "properly restrict the use of" the alloca function when allocating the SPECS array, which allows context-dependent attackers to bypass the FORTIFY_SOURCE format-string protection mechanism and cause a denial of service (crash) or possibly execute arbitrary code via a crafted format string using positional parameters and a large number of format specifiers, a different vulnerability than CVE-2012-3404 and CVE-2012-3405.

Integer overflow in the vfprintf function in stdio-common/vfprintf.c in glibc 2.14 and other versions allows context-dependent attackers to bypass the FORTIFY_SOURCE protection mechanism, conduct format string attacks, and write to arbitrary memory via a large number of arguments.

Multiple directory traversal vulnerabilities in GNU C Library (aka glibc or libc6) before 2.20 allow context-dependent attackers to bypass ForceCommand restrictions and possibly have other unspecified impact via a .. (dot dot) in a (1) LC_*, (2) LANG, or other locale environment variable.

Glibc: stack read overflow in getaddrinfo in no-aaaa mode

Buffer overread in ns_printrrf with corrupted RDATA field

The ADDW macro in stdio-common/vfscanf.c in the GNU C Library (aka glibc or libc6) before 2.21 does not properly consider data-type size during a risk-management decision for use of the alloca function, which might allow context-dependent attackers to cause a denial of service (segmentation violation) or overwrite memory locations beyond the stack boundary via a long line containing wide characters that are improperly handled in a wscanf call.

locale/programs/locale.c in locale in the GNU C Library (aka glibc or libc6) before 2.13 does not quote its output, which might allow local users to gain privileges via a crafted localization environment variable, in conjunction with a program that executes a script that uses the eval function.

scanf and related functions in glibc before 2.15 allow local users to cause a denial of service (segmentation fault) via a large string of 0s.

Calling NSS-backed functions that support caching via nscd may call the nscd client side code and in the GNU C Library version 2.36 under high load on x86_64 systems, the client may call memcmp on inputs that are concurrently modified by other processes or threads and crash. The nscd client in the GNU C Library uses the memcmp function with inputs that may be concurrently modified by another thread, potentially resulting in spurious cache misses, which in itself is not a security issue.  However in the GNU C Library version 2.36 an optimized implementation of memcmp was introduced for x86_64 which could crash when invoked with such undefined behaviour, turning this into a potential crash of the nscd client and the application that uses it. This implementation was backported to the 2.35 branch, making the nscd client in that branch vulnerable as well.  Subsequently, the fix for this issue was backported to all vulnerable branches in the GNU C Library repository. It is advised that distributions that may have cherry-picked the memcpy SSE2 optimization in their copy of the GNU C Library, also apply the fix to avoid the potential crash in the nscd client.

Stack-based buffer overflow in the clntudp_call function in sunrpc/clnt_udp.c in the GNU C Library (aka glibc or libc6) allows remote servers to cause a denial of service (crash) or possibly unspecified other impact via a flood of crafted ICMP and UDP packets.

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.

The pop_fail_stack function in the GNU C Library (aka glibc or libc6) allows context-dependent attackers to cause a denial of service (assertion failure and application crash) via vectors related to extended regular expression processing.

The fnmatch function in the GNU C Library (aka glibc or libc6) before 2.22 might allow context-dependent attackers to cause a denial of service (application crash) via a malformed pattern, which triggers an out-of-bounds read.

Use-after-free vulnerability in the clntudp_call function in sunrpc/clnt_udp.c in the GNU C Library (aka glibc or libc6) before 2.26 allows remote attackers to have unspecified impact via vectors related to error path.

The DNS stub resolver in the GNU C Library (aka glibc or libc6) before version 2.26, when EDNS support is enabled, will solicit large UDP responses from name servers, potentially simplifying off-path DNS spoofing attacks due to IP fragmentation.

Glibc: potential use-after-free in gaih_inet()

Glibc: potential use-after-free in getaddrinfo()

The glob function in glob.c in the GNU C Library (aka glibc or libc6) before 2.27, when invoked with GLOB_TILDE, could skip freeing allocated memory when processing the ~ operator with a long user name, potentially leading to a denial of service (memory leak).

nscd: Null pointer crashes after notfound response

The strcmp implementation optimized for the Power10 processor in the GNU C Library version 2.39 and later writes to vector registers v20 to v31 without saving contents from the caller (those registers are defined as non-volatile registers by the powerpc64le ABI), resulting in overwriting of its contents and potentially altering control flow of the caller, or leaking the input strings to the function to other parts of the program.

The strncmp implementation optimized for the Power10 processor in the GNU C Library version 2.40 and later writes to vector registers v20 to v31 without saving contents from the caller (those registers are defined as non-volatile registers by the powerpc64le ABI), resulting in overwriting of its contents and potentially altering control flow of the caller, or leaking the input strings to the function to other parts of the program.

The iconv function in the GNU C Library (aka glibc or libc6) 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 GNU C Library (aka glibc or libc6) 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, a seen when passing a 0x5d414141414141410000 value to sinl on x86 targets. This is related to sysdeps/ieee754/ldbl-96/e_rem_pio2l.c.

In the GNU C Library (aka glibc or libc6) 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.

The process_envvars function in elf/rtld.c in the GNU C Library (aka glibc or libc6) before 2.23 allows local users to bypass a pointer-guarding protection mechanism via a zero value of the LD_POINTER_GUARD environment variable.