CVE-2021-21806
CWE-416Published: July 8, 2021· Updated: Jun 17, 2026
Official Description
An exploitable use-after-free vulnerability exists in WebKitGTK browser version 2.30.3 x64. A specially crafted HTML web page can cause a use-after-free condition, resulting in remote code execution. The victim needs to visit a malicious web site to trigger the vulnerability.
Technical Analysis
CVE-2021-21806 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
Exploitation does not require any privileges, though user interaction (Required) is needed, which slightly reduces the risk of mass automated attacks.
A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 8.8.
From a weakness classification perspective (CWE-416): Use-after-free vulnerabilities involve accessing memory after it has been freed, often enabling arbitrary code execution.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (4)
Quick Facts
Related CVEs (CWE-416)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2021-21806 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts