CVE-2023-28320
CWE-400Published: May 26, 2023· Updated: Jun 17, 2026
Official Description
A denial of service vulnerability exists in curl <v8.1.0 in the way libcurl provides several different backends for resolving host names, selected at build time. If it is built to use the synchronous resolver, it allows name resolves to time-out slow operations using `alarm()` and `siglongjmp()`. When doing this, libcurl used a global buffer that was not mutex protected and a multi-threaded application might therefore crash or otherwise misbehave.
Technical Analysis
CVE-2023-28320 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
A successful exploit results in availability disruption (denial of service), with a CVSS base score of 5.9.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (18)
Quick Facts
Related CVEs (CWE-400)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2023-28320 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts