Buffer overflow in Cesanta Mongooseos Mjs
CVE-2021-31875
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 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."
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.022 (81.6th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 82nd percentile — 81.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.022 · newest: 0.022 · change: 0.000
Affected products
- Cesanta Mongooseos Mjs — versions 1.26
Weakness classification (CWE)
References
- huntr.dev/bounties/1-other-mjs/ (Exploit, Third Party Advisory)
- github.com/418sec/mjs/pull/2 (Patch, Third Party Advisory)
- github.com/cesanta/mjs/releases/tag/1.26 (Third Party Advisory, Release Notes)
Frequently asked questions
- What is CVE-2021-31875?
- CVE-2021-31875 is a critical-severity vulnerability in Cesanta Mongooseos Mjs, classified under Off-by-one Error. CVSS score: 9.8/10. Published 2021-04-29.
- How severe is CVE-2021-31875?
- Critical severity. CVSS v3 base score is 9.8 out of 10.