CVE-2023-45239
Facebook Tac Plus ≤ 2023-10-05
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HSummary
CVE-2023-45239 is a critical-severity Improper Filtering of Special Elements (CWE-790) vulnerability in Facebook Tac Plus. Its CVSS base score is 9.8 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique PowerShell (T1059.001); ranked in the top 23% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
A lack of input validation in tac_plus prior to commit 4fdf178 permits command injection when pre-auth or post-auth commands are enabled. The affected component is the Facebook-maintained tac_plus TACACS+ server, which processes untrusted values for username, rem-addr, and NAC address fields without sanitization.
An unauthenticated network attacker who can influence any of those three fields can inject arbitrary shell commands and obtain remote code execution on the tac_plus server. The vulnerability carries a CVSS 3.1 score of 9.8, reflecting network-accessible exploitation with no required credentials or user interaction.
Advisories published with the GitHub security notice GHSA-p334-5r3g-4vx3 and the associated pull request recommend upgrading to a build that includes commit 4fdf178; downstream distributions such as Fedora have issued corresponding package updates that apply the same fix.
EPSS for the CVE rose from a low baseline to a peak of 0.3589, indicating increased exploitation interest after public disclosure.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-49545
Vulnerability Data
A lack of input validation exists in tac_plus prior to commit 4fdf178 which, when pre or post auth commands are enabled, allows an attacker who can control the username, rem-addr, or NAC address sent to tac_plus to inject shell commands…
more
and gain remote code execution on the tac_plus server.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
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.
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 improper filtering but does not itself implement the filtering control.
Secure development life cycle mandates input validation and sanitization that directly prevents improper filtering of special elements.
Application security requirements explicitly call for input validation controls that mitigate improper special-element filtering.
Secure system architecture and engineering principles include defensive input handling that reduces the risk of unfiltered special elements.
Secure coding standards require proper filtering and encoding of special elements before downstream processing.