CVE-2025-24032
Description
A flaw was found in the pam_pkcs11 Linux-PAM login module. If the cert_policy is set to none, which is the default value, then pam_pkcs11 will only check if the user is capable of logging into the token. This flaw allows an attacker to create a different token with the user's public data, for example, the user's certificate and a PIN known to the attacker. If no signature with the private key is required, the attacker can log in as a user with that created token.
Statement
This vulnerability is of moderate severity because it only applies when the configuration explicitly disables signature verification (cert_policy = none), which is not a secure best practice. The attack requires an adversary to create a fake token using the victim’s public certificate and a known PIN, but it does not compromise the private key itself. Since private key possession is typically required for strong authentication, systems enforcing proper certificate verification (including signature validation) remain unaffected. Additionally, RHEL is not vulnerable by default, further reducing the real-world impact.
Mitigation
Restrict the cert_policy value to `signature` in the pam_pkcs11.conf configuration file (`cert_policy = signature`).
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 8 | N/A | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | None | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | High | N/A | N/A |
| Integrity Impact | High | N/A | N/A |
| Availability Impact | Low | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L
Understanding the Weakness (CWE)
Integrity,Confidentiality,Availability,Access Control
Technical Impact: Read Application Data; Gain Privileges or Assume Identity; Execute Unauthorized Code or Commands
This weakness can lead to the exposure of resources or functionality to unintended actors, possibly providing attackers with sensitive information or even execute arbitrary code.
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