CVE-2023-4039
GCC's-fstack-protector fails to guard dynamically-sized local variables on AArch64
Published Sep 13, 2023 · updated Oct 14, 2026 · Arm Ltd Arm GNU Toolchain
**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.
Timeline
Detection, updates, and resolution for this record.
Sep 13, 2023 · NIST NVD
Detected
**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 int
Oct 14, 2026 · NIST NVD
Updated
**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 int
Affected
- cpe gnu/gccversion unspecified
- vendor Arm Ltd Arm GNU Toolchainversion unspecified
- vendor GNU GCCversion unspecified
Sources
- CIRCL Vulnerability LookupCVE-2023-4039
**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 app
vulnerability.circl.lu - CVE.orgCVE-2023-4039
Official CVE identifier
cve.org - FIRST EPSSCVE-2023-4039
30-day exploitation probability 0.8%
first.org - NIST NVDCVE-2023-4039
**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
nvd.nist.gov