Gcc

**DISPUTED**A failure in the -fstack-protector feature in GCC-based toolchains that target AArch64 allows an attacker to exploit an existing buffer overflow in dynamically-sized local variables in your application without this being detected. This stack-protector failure only applies to C99-style dynamically-sized local variables or those created using alloca(). The stack-protector operates as intended for statically-sized local variables. The default behavior when the stack-protector detects an overflow is to terminate your application, resulting in controlled loss of availability. An attacker who can exploit a buffer overflow without triggering the stack-protector might be able to change program flow control to cause an uncontrolled loss of availability or to go further and affect confidentiality or integrity. NOTE: The GCC project argues that this is a missed hardening bug and not a vulnerability by itself.Show less

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.Show less

The POWER9 backend in GNU Compiler Collection (GCC) before version 10 could optimize multiple calls of the __builtin_darn intrinsic into a single call, thus reducing the entropy of the random number generator. This occurred because a volatile operation was not specified. For example, within a single execution of a program, the output of every __builtin_darn() call may be the same.Show less

stack_protect_prologue in cfgexpand.c and stack_protect_epilogue in function.c in GNU Compiler Collection (GCC) 4.1 through 8 (under certain circumstances) generate instruction sequences when targeting ARM targets that spill the address of the stack protector guard, which allows an attacker to bypass the protection of -fstack-protector, -fstack-protector-all, -fstack-protector-strong, and -fstack-protector-explicit against stack overflow by controlling what the stack canary is compared against.Show less

Under certain circumstances, the ix86_expand_builtin 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.Show less

The std::random_device class in libstdc++ in the GNU Compiler Collection (aka GCC) before 4.9.4 does not properly handle short reads from blocking sources, which makes it easier for context-dependent attackers to predict the random values via unspecified vectors.Show less

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)Show less

gcc 4.3.x does not generate a cld instruction while compiling functions used for string manipulation such as memcpy and memmove on x86 and i386, which can prevent the direction flag (DF) from being reset in violation of ABI conventions and cause data to be copied in the wrong direction during signal handling in the Linux kernel, which might allow context-dependent attackers to trigger memory corruption. NOTE: this issue was originally reported for CPU consumption in SBCL.Show less

fold_binary in fold-const.c in GNU Compiler Collection (gcc) 4.1 improperly handles pointer overflow when folding a certain expr comparison to a corresponding offset comparison in cases other than EQ_EXPR and NE_EXPR, which might introduce buffer overflow vulnerabilities into applications that could be exploited by context-dependent attackers.NOTE: the vendor states that the essence of the issue is "not correctly interpreting an offset to a pointer as a signed value."Show less