dbcve.org
Improper Access ControlWeakness · CWE-284

CVE-2025-1390

MEDIUM · 6.1 CVSS v3.1 Published 2025-02-18
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
63/100
Remediation priority · Elevated
Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
The PAM module pam_cap.so of libcap configuration supports group names starting with “@”, during actual parsing, configurations not starting with “@” are incorrectly recognized as group names. This may result in nonintended users being granted an inherited capability set, potentially leading to security risks. Attackers can exploit this vulnerability to achieve local privilege escalation on systems where /etc/security/capability.conf is used to configure user inherited privileges by constructing specific usernames.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

The pam_cap.so PAM module in libcap has a parsing flaw in /etc/security/capability.conf where configuration entries lacking the '@' prefix are incorrectly interpreted as group names, causing arbitrary users to receive unintended inherited capability sets. This misconfiguration can be weaponized for local privilege escalation by creating usernames that trigger the faulty parsing logic.

MitigationAudit /etc/security/capability.conf to enforce proper '@' prefix syntax for all group entries and verify users receive only intended capabilities; apply vendor patches for libcap when available.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
High
Availability
None

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Verify pam_cap.so is loaded in PAM configuration
    Search PAM configuration files (e.g., /etc/pam.d/*) for lines containing 'pam_cap.so' or 'capability'. Use: grep -r 'pam_cap\|capability' /etc/pam.d/ 2>/dev/null
    Affected if pam_cap.so is not present in any PAM configuration file (not vulnerable as the module is not in use)
  2. Locate and read the capability.conf file
    Check for /etc/security/capability.conf. If it exists, read its contents using: cat /etc/security/capability.conf
    Affected if The file /etc/security/capability.conf does not exist (not vulnerable as no capability assignments are configured)
  3. Identify capability.conf entries without '@' prefix
    Examine each non-comment, non-empty line in /etc/security/capability.conf. Lines should follow format 'capability user' or 'capability @group'. Look for entries that appear to be usernames but lack the '@' prefix. Use: grep -v '^#' /etc/security/capability.conf | grep -v '^$'
    Affected if Any line in capability.conf contains a username (non-group) entry that lacks the '@' prefix before it, causing that username to be misinterpreted as a group name
  4. Check installed libcap version
    Query the installed libcap package version using the system package manager, for example: dpkg -l | grep libcap (Debian/Ubuntu) or rpm -qa | grep libcap (RHEL/CentOS)
    Affected if The installed libcap version is within or below the affected range and pam_cap.so is enabled with vulnerable capability.conf entries
  5. Identify system users that could exploit the parsing flaw
    Compare entries in /etc/security/capability.conf that lack '@' prefix against existing system usernames in /etc/passwd. Any matching username would receive unintended capabilities
    Affected if A username in /etc/passwd matches a capability.conf entry that lacks the '@' prefix, meaning that user receives capabilities intended for a group

A user is affected if pam_cap.so is enabled in PAM configuration AND /etc/security/capability.conf contains entries without '@' prefix that match existing system usernames, allowing unintended capability inheritance.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Audit /etc/security/capability.conf to enforce proper '@' prefix syntax for all group entries and verify users receive only intended capabilities; apply vendor patches for libcap when available.

Have this fixed Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-1390 in production — separate from our analysis above.

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What this is

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What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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