GNU » Glibc : Security Vulnerabilities, CVEs, Published In 2017

glibc contains a vulnerability that allows specially crafted LD_LIBRARY_PATH values to manipulate the heap/stack, causing them to alias, potentially resulting in arbitrary code execution. Please note that additional hardening changes have been made to glibc to prevent manipulation of stack and heap memory but these issues are not directly exploitable, as such they have not been given a CVE. This affects glibc 2.25 and earlier.

The malloc function in the GNU C Library (aka glibc or libc6) 2.26 could return a memory block that is too small if an attempt is made to allocate an object whose size is close to SIZE_MAX, potentially leading to a subsequent heap overflow. This occurs because the per-thread cache (aka tcache) feature enables a code path that lacks an integer overflow check.

elf/dl-load.c in the GNU C Library (aka glibc or libc6) 2.19 through 2.26 mishandles RPATH and RUNPATH containing $ORIGIN for a privileged (setuid or AT_SECURE) program, which allows local users to gain privileges via a Trojan horse library in the current working directory, related to the fillin_rpath and decompose_rpath functions. This is associated with misinterpretion of an empty RPATH/RUNPATH token as the "./" directory. NOTE: this configuration of RPATH/RUNPATH for a privileged program is apparently very uncommon; most likely, no such program is shipped with any common Linux distribution.

The glob function in glob.c in the GNU C Library (aka glibc or libc6) before 2.27 contains a buffer overflow during unescaping of user names with the ~ operator.

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).

The GNU C Library (aka glibc or libc6) before 2.27 contains an off-by-one error leading to a heap-based buffer overflow in the glob function in glob.c, related to the processing of home directories using the ~ operator followed by a long string.

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.

The xdr_bytes and xdr_string 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

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.

Memory leak in the __res_vinit function in the IPv6 name server management code in libresolv in GNU C Library (aka glibc or libc6) before 2.24 allows remote attackers to cause a denial of service (memory consumption) by leveraging partial initialization of internal resolver data structures.

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.

Integer overflow in the _IO_wstr_overflow function in libio/wstrops.c in the GNU C Library (aka glibc or libc6) before 2.22 allows context-dependent attackers to cause a denial of service (application crash) or possibly execute arbitrary code via vectors related to computing a size in bytes, which triggers a heap-based buffer overflow.

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.

res_query in libresolv in glibc before 2.25 allows remote attackers to cause a denial of service (NULL pointer dereference and process crash).

nscd in the GNU C Library (aka glibc or libc6) before version 2.20 does not correctly compute the size of an internal buffer when processing netgroup requests, possibly leading to an nscd daemon crash or code execution as the user running nscd.

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.