CVE-2017-11671: Weak RNG
Under certain circumstances, the ix86expandbuiltin function in i386.c in GNU Compiler Collection (GCC) version 4.6, 4.7, 4.8, 4.9, 5 before 5.5, and 6 before 6.4 will generate instruction sequences that clobber the status flag of the RDRAND and RDSEED intrinsics before it can be read, potentially causing failures of these instructions to go unreported.
Upstream bug:
https://gcc.gnu.org/bugzilla/showbug.cgi?id=80180
Upstream patch:
https://gcc.gnu.org/ml/gcc-patches/2017-03/msg01349.html
References:
http://seclists.org/oss-sec/2017/q3/218
Other sources
Under certain circumstances, the ix86expandbuiltin function in i386.c in GNU Compiler Collection (GCC) version 4.6, 4.7, 4.8, 4.9, 5 before 5.5, and 6 before 6.4 will generate instruction sequences that clobber the status flag of the RDRAND and RDSEED intrinsics before it can be read, potentially causing failures of these instructions to go unreported. This could potentially lead to less randomness in random number generation.
— MITRE
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2017-11671?
CVE-2017-11671 is considered a high severity vulnerability due to its potential impact on the integrity of random number generation.
How do I fix CVE-2017-11671?
To fix CVE-2017-11671, update your GCC version to 5.5 or 6.4 or later.
What is affected by CVE-2017-11671?
CVE-2017-11671 affects GNU Compiler Collection (GCC) versions 4.6 through 6.3.
Can CVE-2017-11671 lead to exploitation?
Yes, CVE-2017-11671 may lead to exploitation by allowing an attacker to predict values from random number generation.
Is CVE-2017-11671 a local or remote vulnerability?
CVE-2017-11671 is primarily considered a local vulnerability impacting applications running with GCC compilers.