Advisories ยป MGASA-2017-0184

Updated glibc packages fixes critical security vulnerabilities

Publication date: 26 Jun 2017
Type: security
Affected Mageia releases : 5
CVE: CVE-2017-8804 , CVE-2017-1000366


The sunrpc implementation in glibc is vulnerable to a flaw that can cause
it to be triggered to allocate additional memory until it causes a crash,
similar to CVE-2017-8779 (CVE-2017-8804).

A flaw was found in the way memory was being allocated on the stack for
user space binaries. If heap (or different memory region) and stack memory
regions were adjacent to each other, an attacker could use this flaw to
jump over the stack guard gap, cause controlled memory corruption on
process stack or the adjacent memory region, and thus increase their
privileges on the system. This is glibc-side mitigation which blocks
processing of LD_LIBRARY_PATH for programs running in secure-execution
mode and reduces the number of allocations performed by the processing
of LD_AUDIT, LD_PRELOAD, and LD_HWCAP_MASK, making successful exploitation
of this issue more difficult (CVE-2017-1000366).

The CVE-2017-1000366 issue is part of a set of issues known as Stack Clash.
The fixes have components in both glibc and the kernel. The kernel fix will
be included in a separate update advisory (mga#21141)