{"cve":"CVE-2023-4039","nvd":{"published":"2023-09-13T09:15:15.690","modified":"2026-10-14T22:17:17.000","status":"Modified","description":"**DISPUTED**A failure in the -fstack-protector feature in GCC-based toolchains \nthat target AArch64 allows an attacker to exploit an existing buffer \noverflow in dynamically-sized local variables in your application \nwithout this being detected. This stack-protector failure only applies \nto C99-style dynamically-sized local variables or those created using \nalloca(). The stack-protector operates as intended for statically-sized \nlocal variables.\n\nThe default behavior when the stack-protector \ndetects an overflow is to terminate your application, resulting in \ncontrolled loss of availability. An attacker who can exploit a buffer \noverflow without triggering the stack-protector might be able to change \nprogram flow control to cause an uncontrolled loss of availability or to\n 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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N","score":4.8},"cwes":["CWE-693"],"references":["https://developer.arm.com/Arm%20Security%20Center/GCC%20Stack%20Protector%20Vulnerability%20AArch64","https://github.com/metaredteam/external-disclosures/security/advisories/GHSA-x7ch-h5rf-w2mf","https://developer.arm.com/Arm%20Security%20Center/GCC%20Stack%20Protector%20Vulnerability%20AArch64","https://github.com/metaredteam/external-disclosures/security/advisories/GHSA-x7ch-h5rf-w2mf","https://cert-portal.siemens.com/productcert/html/ssa-355557.html"],"products":["gnu:gcc"],"source":"nvd","synced_at":"2026-10-19T21:39:24.235896374+00:00"},"epss":{"cve":"CVE-2023-4039","score":0.01036,"percentile":0.6366,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}