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TLS Client Authentication Bypass

Critical
IngelaAndin published GHSA-f7jg-qm7f-ppm8 Sep 11, 2025

Package

OTP

Affected versions

>= 17.0

Patched versions

25.1, 24.3.4.2, 23.3.4.15
ssl (OTP)
>= 5.3.4
10.8.4, 10.7.3.2, 10.3.1.3

Description

Impact

A logical error in the TLS (SSL) implementation allows client certificates to be accepted without checking that the client certificate actually belongs to the client. This should be checked by verifying the signature sent by the client in certificate verify message, but
due to the error this step could be skipped.

Impacted are those who are running an SSL/TLS/DTLS server using the ssl application either directly or indirectly via other applications. For example via inets (httpd), cowboy, etc. Note that the vulnerability only affects servers that request client certification, that is sets the option {verify, verify_peer}.

Affected/Unaffected Versions

A version larger than or equal to one of the listed patched versions is unaffected; otherwise, a version that satisfies an expression listed under affected versions is affected, and if it does not, it is unaffected.

The documentation of the new OTP version scheme describes how versions should be compared. Note that versions used prior to OTP 17.0, when the new OTP version scheme was introduced, are never listed since it is not well defined how to compare those versions.

In the case of this vulnerability, versions prior to OTP 17.0 are likely also affected.

Severity

Critical

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVE ID

CVE-2022-37026

Weaknesses

Improper Authentication

When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. Learn more on MITRE.