{"cve":"CVE-2023-40271","nvd":{"published":"2023-09-08T02:15:08.133","modified":"2026-06-17T06:16:57.493","status":"Modified","description":"In Trusted Firmware-M through TF-Mv1.8.0, for platforms that integrate the CryptoCell accelerator, when the CryptoCell PSA Driver software Interface is selected, and the Authenticated Encryption with Associated Data Chacha20-Poly1305 algorithm is used, with the single-part verification function (defined during the build-time configuration phase) implemented with a dedicated function (i.e., not relying on usage of multipart functions), the buffer comparison during the verification of the authentication tag does not happen on the full 16 bytes but just on the first 4 bytes, thus leading to the possibility that unauthenticated payloads might be identified as authentic. This affects TF-Mv1.6.0, TF-Mv1.6.1, TF-Mv1.7.0, and TF-Mv1.8.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","score":7.5},"cwes":["CWE-697"],"references":["https://git.trustedfirmware.org/TF-M/trusted-firmware-m.git/tree/docs/security/security_advisories/cc3xx_partial_tag_compare_on_chacha20_poly1305.rst","https://tf-m-user-guide.trustedfirmware.org/releases/index.html","https://git.trustedfirmware.org/TF-M/trusted-firmware-m.git/tree/docs/security/security_advisories/cc3xx_partial_tag_compare_on_chacha20_poly1305.rst","https://tf-m-user-guide.trustedfirmware.org/releases/index.html"],"products":["trustedfirmware:trusted_firmware-m"],"source":"nvd","synced_at":"2026-10-19T21:39:24.235896374+00:00"},"epss":{"cve":"CVE-2023-40271","score":0.00386,"percentile":0.32723,"date":"2026-10-31"},"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."]}