Bleichenbacher padding oracle in PKCS#7 KTRI RSA PKCS#1 v1.5 decryption (wolfSSL wolfSSL)

CVE-2026-6291
MEDIUM 6.0

En bref

Source
NVD
EPSS
EPSS 0.24 % · centile 16 ()
État
PUBLISHED
Publiée
Mise à jour
Attribuée par
wolfSSL
Statut NVD
Analyzed

Description

Bleichenbacher padding oracle in PKCS#7 KTRI decryption. When decrypting PKCS#7 EnvelopedData using RSA PKCS#1 v1.5 key transport, wolfSSL returned distinguishable error codes depending on whether RSA padding validation failed versus whether the decrypted content was malformed. An attacker able to submit crafted EnvelopedData messages and observe error responses could use this as a padding oracle to incrementally recover the encrypted Content Encryption Key (CEK). The fix generates a deterministic pseudo-random fake CEK on padding failure (via HMAC-SHA256) and proceeds with decryption identically, using constant-time operations throughout, so that all failure paths produce the same error regardless of padding validity.

Faiblesses (CWE)

  • CWE-208 — Écart de temps observable

Références

Scores

VersionScoreVecteurÉvalué par
CVSS 4.0MEDIUM 6.0CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:NwolfSSL
CVSS 4.0MEDIUM 6.0CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XNVD · facts@wolfssl.com (Secondary)
CVSS 3.1MEDIUM 6.5CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:NNVD · nvd@nist.gov (Primary)

Références européennes

Configurations affectées (CPE NVD)

Produits affectés

ProduitVersions
wolfSSL · wolfSSLaffected 3.9.10 ≤ 5.9.1

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD