CVE-2023-25135
Published: 03 February 2023
Summary
CVE-2023-25135 is a critical-severity Deserialization of Untrusted Data (CWE-502) vulnerability in Vbulletin Vbulletin. Its CVSS base score is 9.8 (Critical).
Operationally, ranked in the top 0.2% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
Deeper analysis
vBulletin before 5.6.9 PL1 contains a deserialization flaw in the verify_serialized function, which attempts to validate serialized data by calling unserialize and inspecting for errors rather than using a safe inspection method. This affects the vBulletin forum software and is tracked as CWE-502 with a CVSS 3.1 score of 9.8.
An unauthenticated remote attacker can supply a crafted HTTP request that triggers unsafe deserialization, resulting in arbitrary code execution on the server and full compromise of confidentiality, integrity, and availability.
Official vBulletin announcements direct administrators to apply the security patches released in versions 5.6.7 PL1, 5.6.8 PL1, and 5.6.9 PL1. The current EPSS score of 0.9334 reflects a high likelihood of exploitation, consistent with public technical write-ups that detail the bypass technique.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-29114
Vulnerability details
vBulletin before 5.6.9 PL1 allows an unauthenticated remote attacker to execute arbitrary code via a crafted HTTP request that triggers deserialization. This occurs because verify_serialized checks that a value is serialized by calling unserialize and then checking for errors. The…
more
fixed versions are 5.6.7 PL1, 5.6.8 PL1, and 5.6.9 PL1.
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Penetration testing supplies malicious serialized objects, detecting unsafe deserialization and supporting corrective actions.
Evaluation of untrusted data handling (deserialization testing) reveals unsafe processing, which the required remediation process addresses.
Untrusted serialized data can be deserialized and observed inside the chamber, blocking gadget-chain exploitation outside the sandbox.
Validates or rejects untrusted serialized data before deserialization occurs.
Identifies and blocks malicious code introduced through deserialization of untrusted data at system boundaries.
Integrity verification of serialized information can detect tampering before deserialization occurs.
Provenance of associated data allows detection of untrusted sources before deserialization or processing occurs.