CVE-2022-25845
Published: 10 June 2022
Summary
CVE-2022-25845 is a high-severity Deserialization of Untrusted Data (CWE-502) vulnerability in Alibaba Fastjson. Its CVSS base score is 8.1 (High).
Operationally, ranked in the top 0.5% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
Deeper analysis
The package com.alibaba:fastjson prior to version 1.2.83 contains a deserialization of untrusted data vulnerability that allows bypass of the library's default autoType shutdown restrictions under certain conditions. The flaw is tracked as CWE-502 and carries a CVSS 3.1 score of 8.1 with a network attack vector requiring no authentication or user interaction.
An attacker able to supply crafted JSON input to an application using the affected library can trigger remote code execution or other high-impact actions against the target server. Exploitation succeeds when the application accepts and processes untrusted data through Fastjson's deserialization routines without additional safeguards.
Vendor guidance and patches direct users to upgrade to Fastjson 1.2.83, which contains the fixes committed in the referenced pull requests. When an upgrade is not feasible, the documented workaround is to enable safeMode as described in the project's security update and wiki documentation.
The associated EPSS score has remained at a high level near 0.88–0.90.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2022-6120
Vulnerability details
The package com.alibaba:fastjson before 1.2.83 are vulnerable to Deserialization of Untrusted Data by bypassing the default autoType shutdown restrictions, which is possible under certain conditions. Exploiting this vulnerability allows attacking remote servers. Workaround: If upgrading is not possible, you can…
more
enable [safeMode](https://github.com/alibaba/fastjson/wiki/fastjson_safemode).
- 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.