DoTls13CertificateVerify in tls13.c in wolfSSL before 4.7.0 does not cease processing for certain anomalous peer behavior (sending an ED225…

published 2021-01-29 5y ago modified 2026-06-17 4mo ago also EUVD-2021-26667

cvss: 8.1; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.8%; EPSS 0.8% chance of exploitation in 30 days, percentile 56%
public exploits: 0; none known

DoTls13CertificateVerify in tls13.c in wolfSSL before 4.7.0 does not cease processing for certain anomalous peer behavior (sending an ED22519, ED448, ECC, or RSA signature without the corresponding certificate). The client side is affected because man-in-the-middle attackers can impersonate TLS 1.3 servers.

Patch / fix

fixed in 1 distros 1 links 1

wolfssl wolfssl 4.7.0

wolfssl Debian 13, Debian 12 4.6.0-3

debian advisories DEBIAN-CVE-2021-3336

github.com/wolfSSL/wolfssl#3676 pull request

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Exploit prediction

0.80% chance of exploitation in the next 30 days, higher than 56% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by	version	score	vector
NVD	3.1	8.1	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	2.0	6.8	AV:N/AC:M/Au:N/C:P/I:P/A:P

Classification

Weakness

CWE-295 Improper Certificate Validation

References

github.com /wolfSSL/wolfssl/pull/3676
patch, third-party-advisory
wolfssl.com /docs/security-vulnerabilities
vendor-advisory

Sources

CVE List CVE-2021-3336
NVD CVE-2021-3336

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