CVE-2024-39691
Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:NSummary
CVE-2024-39691 is a medium-severity Improper Handling of Insufficient Permissions or Privileges (CWE-280) vulnerability. Its CVSS base score is 4.3 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Client Execution (T1203); ranked at the 40th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SC-24 (Fail in Known State) and SI-17 (Fail-safe Procedures) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2024-2434
Vulnerability Data
matrix-appservice-irc is a Node.js IRC bridge for the Matrix messaging protocol. The fix for GHSA-wm4w-7h2q-3pf7 / CVE-2024-32000 included in matrix-appservice-irc 2.0.0 relied on the Matrix homeserver-provided timestamp to determine whether a user has access to the event they're replying to…
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when determining whether or not to include a truncated version of the original event in the IRC message. Since this value is controlled by external entities, a malicious Matrix homeserver joined to a room in which a matrix-appservice-irc bridge instance (before version 2.0.1) is present can fabricate the timestamp with the intent of tricking the bridge into leaking room messages the homeserver should not have access to. matrix-appservice-irc 2.0.1 drops the reliance on `origin_server_ts` when determining whether or not an event should be visible to a user, instead tracking the event timestamps internally. As a workaround, it's possible to limit the amount of information leaked by setting a reply template that doesn't contain the original message.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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- 7 hardening rules · 3 OS baselines
V6.2.2V8.3.3
Mitigating Controls (NIST 800-53 r5) AI
Requires the system to fail to a known safe state on specified failures, limiting the impact of unhandled exceptional conditions.
Mandates explicit fail-safe procedures triggered by indicated failures, structurally preventing unhandled or mishandled exceptional conditions.
Ensuring access decisions are applied to every request structurally prevents the product from taking unexpected paths when privileges are lacking.
A reference monitor that is always invoked guarantees privilege checks occur, eliminating the root condition for improper insufficient-privilege handling.
Access enforcement directly stops code from proceeding on insufficient privileges by applying authorization checks before resource access.
Requires generation of appropriate error messages on exceptional conditions, directly enforcing correct handling rather than silent or incorrect behavior.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Defining, enforcing and reviewing access permissions with least privilege directly prevents code paths that mishandle insufficient privileges.
Secure SDLC practices explicitly require proper exception and error handling during design and coding.
Runtime monitoring of software and data surfaces adverse events triggered by unhandled permission failures.
Generating logs of permission-related events enables detection and analysis of improper handling.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing can detect missing or incorrect privilege handling.
Defines access-control policy that should prevent insufficient-privilege situations.
Specifies how access rights are granted, reviewed and revoked, directly addressing privilege handling.
Documented operating procedures may specify exception handling but do not guarantee implementation.
Logging captures unhandled exceptions, aiding detection but not preventing the weakness.
Monitoring can surface unhandled exceptions but does not enforce proper handling.
Hardening callouts derived
Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).
Oracle Linux 8 (2 rules)
- V-248548 OL 8 must use a Linux Security Module configured to enforce limits on system services. prevents CWE-280
- V-248596 OL 8 must enable the SELinux targeted policy. prevents CWE-280
Oracle Linux 9 (1 rule)
- V-271452 OL 9 must use a Linux Security Module configured to enforce limits on system services. prevents CWE-280
RHEL 9 (2 rules)
- V-258078 RHEL 9 must use a Linux Security Module configured to enforce limits on system services. prevents CWE-280
- V-272496 RHEL 9 must elevate the SELinux context when an administrator calls the sudo command. prevents CWE-280