SB2016020812 - Fedora 22 update for glibc

Description

This security bulletin contains information about 3 secuirty vulnerabilities.

1) Stack-based buffer overflow (CVE-ID: CVE-2015-7547)

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The weakness exists due to stack-based buffer overflow in in the (1) send_dg and (2) send_vc functions in the libresolv library. A remote attacker can use a crafted DNS response that triggers a call to the getaddrinfo function with the AF_UNSPEC or AF_INET6 address family, related to performing "dual A/AAAA DNS queries" and the libnss_dns.so.2 NSS module, cause memory corruption and execute arbitrary code.

Successful exploitation of the vulnerability may result in system compromise.

2) Security features bypass (CVE-ID: CVE-2015-8777)

The vulnerability allows a local user to manipulate data.

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.

3) Buffer overflow (CVE-ID: CVE-2015-1781)

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to buffer overflow in the gethostbyname_r and other unspecified NSS functions in the GNU C Library (aka glibc or libc6). A remote attacker can create a specially crafted file and execute arbitrary code on the target system.

Remediation

Install update from vendor's website.

References

• https://bodhi.fedoraproject.org/updates/FEDORA-2016-0480defc94