CVE-2021-3939
7.8 · HIGHOverview
CVE-2021-3939 is a high-severity vulnerability affecting canonical accountsservice. It was published on November 17, 2021 and has a CVSS 3.1 base score of 7.8 (HIGH).
This vulnerability has a CVSS 3.1 base score of 7.8, rated HIGH. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.
Technical Description
Ubuntu-specific modifications to accountsservice (in patch file debian/patches/0010-set-language.patch) caused the fallback_locale variable, pointing to static storage, to be freed, in the user_change_language_authorized_cb function. This is reachable via the SetLanguage dbus function. This is fixed in versions 0.6.55-0ubuntu12~20.04.5, 0.6.55-0ubuntu13.3, 0.6.55-0ubuntu14.1.
Remediation
Check the references section for vendor advisories and patches from canonical. Update accountsservice to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| canonical | accountsservice | >= 0.6.55-0ubuntu12\~20.04, < 0.6.55-0ubuntu12\~20.05 | Affected |
References
Frequently Asked Questions
What is CVE-2021-3939?
CVE-2021-3939 is a high-severity vulnerability affecting canonical accountsservice. It was published on November 17, 2021 and has a CVSS 3.1 base score of 7.8 (HIGH).
How severe is CVE-2021-3939?
This vulnerability has a CVSS 3.1 base score of 7.8, rated HIGH. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.
How do I fix or remediate CVE-2021-3939?
Check the references section for vendor advisories and patches from canonical. Update accountsservice to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2021-3939?
CyberStrike's AI-powered security agents can automatically detect CVE-2021-3939 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
Automated penetration testing that runs continuously, not just quarterly.
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