CVE-2021-31875
Published: 29 April 2021
Summary
CVE-2021-31875 is a critical-severity Off-by-one Error (CWE-193) vulnerability in Cesanta Mongooseos Mjs. Its CVSS base score is 9.8 (Critical).
Operationally, ranked in the top 29.7% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2021-18750
Vulnerability details
In mjs_json.c in Cesanta MongooseOS mJS 1.26, a maliciously formed JSON string can trigger an off-by-one heap-based buffer overflow in mjs_json_parse, which can potentially lead to redirection of control flow. NOTE: the original reporter disputes the significance of this finding…
more
because "there isn’t very much of an opportunity to exploit this reliably for an information leak, so there isn’t any real security impact."
- 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.
Out-of-bounds writes that corrupt control flow or inject shellcode are rendered non-executable by the same memory protections.