CVE-2021-31875

Public Exploit

Description

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."

Category

9.8
CVSS
Severity: Critical
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.55%
Third-Party Advisory github.com Third-Party Advisory github.com Third-Party Advisory huntr.dev
Affected: n/a n/a
Published at:
Updated at:

References

Link Tags
https://huntr.dev/bounties/1-other-mjs/ third party advisory exploit
https://github.com/418sec/mjs/pull/2 third party advisory patch
https://github.com/cesanta/mjs/releases/tag/1.26 third party advisory release notes

Frequently Asked Questions

What is the severity of CVE-2021-31875?
CVE-2021-31875 has been scored as a critical severity vulnerability.
How to fix CVE-2021-31875?
To fix CVE-2021-31875, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-31875 being actively exploited in the wild?
It is possible that CVE-2021-31875 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~1% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
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