CVE-2021-20235
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.
Does this matter?
EPSS puts the probability of exploitation in the next 30 days at 43.9%, higher than 99% of all known CVEs. Patch or mitigate before the next change window.
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 3.1
- 8.1 HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 43.86% probability · 99th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-120, CWE-787
- Affected
- zeromq/libzmq
- Source
- secalert@redhat.com
References
- https://bugzilla.redhat.com/show_bug.cgi?id=1921983Issue Tracking, Patch, Third Party Advisory
- https://github.com/zeromq/libzmq/security/advisories/GHSA-fc3w-qxf5-7hp6Patch, Third Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1921983Issue Tracking, Patch, Third Party Advisory
- https://github.com/zeromq/libzmq/security/advisories/GHSA-fc3w-qxf5-7hp6Patch, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.