Vulnerability Description
There's a flaw in the zeromq server in versions before 4.3.3 in src/decoder_allocators.hpp. The decoder static allocator could have its sized changed, but the buffer would remain the same as it is a static buffer. A remote, unauthenticated attacker who sends a crafted request to the zeromq server could trigger a buffer overflow WRITE of arbitrary data if CURVE/ZAP authentication is not enabled. The greatest impact of this flaw is to application availability, data integrity, and confidentiality.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Zeromq | Libzmq | >= 4.2.0, < 4.3.3 |
Related Weaknesses (CWE)
References
- https://bugzilla.redhat.com/show_bug.cgi?id=1921983Issue TrackingPatchThird Party Advisory
- https://github.com/zeromq/libzmq/security/advisories/GHSA-fc3w-qxf5-7hp6PatchThird Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1921983Issue TrackingPatchThird Party Advisory
- https://github.com/zeromq/libzmq/security/advisories/GHSA-fc3w-qxf5-7hp6PatchThird Party Advisory
FAQ
What is CVE-2021-20235?
CVE-2021-20235 is a vulnerability with a CVSS score of 8.1 (HIGH). There's a flaw in the zeromq server in versions before 4.3.3 in src/decoder_allocators.hpp. The decoder static allocator could have its sized changed, but the buffer would remain the same as it is a s...
How severe is CVE-2021-20235?
CVE-2021-20235 has been rated HIGH with a CVSS base score of 8.1/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2021-20235?
Check the references section above for vendor advisories and patch information. Affected products include: Zeromq Libzmq.