DISPUTED gcc 4.2.0 through 4.3.0 in GNU Compiler Collection, when casts are not used, considers the sum of a pointer and an int to be greater than or equal to the pointer, which might lead to removal of length testing code that was intended as a protection mechanism against integer overflow and buffer overflow attacks, and provide no diagnostic message about this removal. NOTE: the vendor has determined that this compiler behavior is correct according to section 6.5.6 of the C99 standard (aka ISO/IEC 9899:1999).
It was discovered that the std::randomdevice class in libstdc++ would not properly detect short reads and could return return predictable values if applications used it to obtain randomness from a blocking source such as /dev/random.
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
GCC v12.0 was discovered to contain an uncontrolled recursion via the component libiberty/rust-demangle.c. This vulnerability allows attackers to cause a Denial of Service (DoS) by consuming excessive CPU and memory resources.
libiberty/rust-demangle.c in GNU GCC 11.2 allows stack consumption in demangleconst, as demonstrated by nm-new.
Multiple integer overflow issues were found in libgfortran, the run-time support library for the Fortran compiler. These could possibly be used to crash a Fortran application or cause it to execute arbitrary code.
Upstream fix:
https://gcc.gnu.org/viewcvs/gcc?limitchanges=0&view=revision&revision=211721
These will be included in a later release of GCC.
References:
http://seclists.org/oss-sec/2014/q3/230