CVE-2023-0547 is a medium-severity vulnerability affecting Mozilla Thunderbird, specifically versions from 68 to 102.9.1. This vulnerability allows the acceptance of revoked certificates when sending S/MIME encrypted emails, as the Online Certificate Status Protocol (OCSP) revocation status of recipient certificates is not checked. The integrity of messages may be compromised, posing risks to sensitive communications.
The CVSS score for this vulnerability is 6.5, indicating medium severity. The attack vector is network-based with low complexity, requiring no privileges and user interaction. Organizations using affected versions of Thunderbird should prioritize remediation, as the failure to address this vulnerability could lead to significant integrity impacts.
Organizations should prioritize patching immediately, as the potential for exploitation exists due to the lack of certificate revocation checks. The urgency for defenders is high, considering the integrity implications of this vulnerability.
As of the last update, there are no known exploits related to this vulnerability, but organizations should remain vigilant and monitor for any emerging threats.
Vulnerability Details
The official description of the vulnerability states that OCSP revocation status of recipient certificates was not checked when sending S/MIME encrypted email, allowing revoked certificates to be accepted. The affected product is Mozilla Thunderbird, with the vulnerability impacting all versions prior to 102.10.
The vulnerability is classified under CWE-295, which pertains to the improper certificate validation. Organizations should take the necessary steps to update to the patched version of Thunderbird (102.10) to mitigate the risk.
This vulnerability was published on June 2, 2023, and has been modified since its initial disclosure.
Technical Analysis
The root cause of this vulnerability lies in the failure to check the revocation status of certificates. The attack vector is network-based, and the attack complexity is low. No privileges are required for exploitation, but user interaction is necessary, as users must send emails with affected versions of Thunderbird.
The impact on confidentiality is none, while the integrity impact is high. The availability impact is also none. This means that while the confidentiality of messages sent is not at risk, the integrity of the messages is at high risk due to the acceptance of potentially revoked certificates.
Risk & Impact Analysis
The real-world risk of this vulnerability includes the potential for attackers to exploit the lack of certificate revocation checks to send fraudulent or malicious emails that appear legitimate. This can lead to unauthorized access to sensitive information and compromise the integrity of communications.
Organizations using affected versions of Thunderbird should assess their usage and prioritize the upgrade to version 102.10. The urgency for remediation is classified as high due to the implications for message integrity and the risk of exploitation.
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
All versions of Mozilla Thunderbird prior to 102.10 are affected by this vulnerability. Organizations should ensure their systems are updated to the latest version to protect against potential exploitation.
Mitigation & Remediation
To mitigate this vulnerability, organizations should upgrade to Thunderbird version 102.10 or later. If an immediate upgrade is not possible, consider implementing configuration changes to limit the impact and exposure to S/MIME email vulnerabilities.
Organizations may also consider enhancing network controls and monitoring for any unusual email behaviors that may indicate exploitation attempts. Regular security assessments can help identify any additional vulnerabilities in the environment.
For ongoing security validation, organizations should implement continuous security testing to ensure that configurations remain secure and vulnerabilities are promptly addressed.
For more information on continuous security testing, refer to our penetration testing services to validate your security posture.
Detection Guidance
Organizations should monitor logs for any indicators of exploitation, such as unauthorized access attempts or unexpected email behaviors. Behavioral anomalies in email transmission should also be flagged for further analysis.
Network signatures for known malicious email patterns can aid in detecting potential exploitation attempts. Regular review and updating of detection rules can enhance the ability to catch emerging threats.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2023-0547 highlights the importance of proper certificate validation in email communications. This vulnerability serves as a reminder for organizations to implement robust security controls and practices around email security.
Security teams should learn from this incident and ensure that certificate revocation checks are enforced in their email systems. Regular training and awareness programs can help mitigate risks associated with certificate-based vulnerabilities.
Organizations can enhance their security posture by integrating best practices from the penetration testing methodology to identify and address vulnerabilities proactively.
For insights into emerging trends in vulnerability exposure, organizations can refer to our 2025 vulnerability exposure severity trends report, which outlines critical insights for future security planning.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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