Ubuntu: USN-2985-2: GNU C Library regression

USN-2985-1 fixed vulnerabilities in the GNU C Library. The fix for CVE-2014-9761introduced a regression which affected applications that use the libm library but were not fully restarted after the upgrade. This update removes the fix forCVE-2014-9761and a future update will be provided to address this issue.

We apologize for the inconvenience.

Original advisory details:

Martin Carpenter discovered that pt_chown in the GNU C Library did not properly check permissions for tty files. A local attacker could use this to gain administrative privileges or expose sensitive information. (CVE-2013-2207,CVE-2016-2856) Robin Hack discovered that the Name Service Switch (NSS) implementation in the GNU C Library did not properly manage its file descriptors. An attacker could use this to cause a denial of service (infinite loop). (CVE-2014-8121) Joseph Myers discovered that the GNU C Library did not properly handle long arguments to functions returning a representation of Not a Number (NaN). An attacker could use this to cause a denial of service (stack exhaustion leading to an application crash) or possibly execute arbitrary code. (CVE-2014-9761) Arjun Shankar discovered that in certain situations the nss_dns code in the GNU C Library did not properly account buffer sizes when passed an unaligned buffer. An attacker could use this to cause a denial of service or possibly execute arbitrary code. (CVE-2015-1781) Sumit Bose and Lukas Slebodnik discovered that the Name Service Switch (NSS) implementation in the GNU C Library did not handle long lines in the files databases correctly. A local attacker could use this to cause a denial of service (application crash) or possibly execute arbitrary code. (CVE-2015-5277) Adam Nielsen discovered that the strftime function in the GNU C Library did not properly handle out-of-range argument data. An attacker could use this to cause a denial of service (application crash) or possibly expose sensitive information. (CVE-2015-8776) Hector Marco and Ismael Ripoll discovered that the GNU C Library allowed the pointer-guarding protection mechanism to be disabled by honoring the LD_POINTER_GUARD environment variable across privilege boundaries. A local attacker could use this to exploit an existing vulnerability more easily. (CVE-2015-8777) Szabolcs Nagy discovered that the hcreate functions in the GNU C Library did not properly check its size argument, leading to an integer overflow. An attacker could use to cause a denial of service (application crash) or possibly execute arbitrary code. (CVE-2015-8778) Maksymilian Arciemowicz discovered a stack-based buffer overflow in the catopen function in the GNU C Library when handling long catalog names. An attacker could use this to cause a denial of service (application crash) or possibly execute arbitrary code. (CVE-2015-8779) Florian Weimer discovered that the getnetbyname implementation in the GNU C Library did not properly handle long names passed as arguments. An attacker could use to cause a denial of service (stack exhaustion leading to an application crash). (CVE-2016-3075)