CVE-2021-20235 describes a buffer overflow vulnerability in ZeroMQ (libzmq) versions prior to 4.3.3, specifically within the src/decoder_allocators.hpp component. A remote, unauthenticated attacker can trigger this flaw by sending a crafted request to a ZeroMQ server, leading to arbitrary data writes if CURVE/ZAP authentication is not enabled. This vulnerability carries a high CVSS score of 8.1, indicating potential severe impacts on application availability, data integrity, and confidentiality due to its network-based attack vector and low attack complexity. Currently, there is no evidence of active exploitation, public exploit code (Metasploit, Nuclei, ExploitDB), or significant community discussion surrounding this CVE.
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
>= 4.2.0, < 4.3.3CPE matchmatch criteria | cpe:2.3:a:zeromq:libzmq:*:*:*:*:*:*:*:* |
CVSS version used by this source: 3.1
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
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