CVE-2021-23993
6.5 · MEDIUMOverview
CVE-2021-23993 is a medium-severity vulnerability affecting mozilla thunderbird. It was published on June 24, 2021 and has a CVSS 3.1 base score of 6.5 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 6.5, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical Description
An attacker may perform a DoS attack to prevent a user from sending encrypted email to a correspondent. If an attacker creates a crafted OpenPGP key with a subkey that has an invalid self signature, and the Thunderbird user imports the crafted key, then Thunderbird may try to use the invalid subkey, but the RNP library rejects it from being used, causing encryption to fail. This vulnerability affects Thunderbird < 78.9.1.
Remediation
Check the references section for vendor advisories and patches from mozilla. Update thunderbird 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 |
|---|---|---|---|
| mozilla | thunderbird | >= 0, < 78.9.1 | Affected |
Frequently Asked Questions
What is CVE-2021-23993?
CVE-2021-23993 is a medium-severity vulnerability affecting mozilla thunderbird. It was published on June 24, 2021 and has a CVSS 3.1 base score of 6.5 (MEDIUM).
How severe is CVE-2021-23993?
This vulnerability has a CVSS 3.1 base score of 6.5, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2021-23993?
Check the references section for vendor advisories and patches from mozilla. Update thunderbird 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-2021-23993?
CyberStrike's AI-powered security agents can automatically detect CVE-2021-23993 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
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