CVE-2023-43770 is a medium-severity cross-site scripting (XSS) vulnerability affecting Roundcube versions prior to 1.4.14, 1.5.x before 1.5.4, and 1.6.x before 1.6.3. This vulnerability allows attackers to craft malicious links within text/plain email messages, leading to potential exploitation. The behavior observed in the program/lib/Roundcube/rcube_string_replacer.php file contributes to this risk.
The CVSS score for this vulnerability is 6.1, indicating a medium severity level. The attack vector is network-based, with low complexity required for exploitation. User interaction is necessary, as victims must open crafted emails to trigger the XSS. Organizations using affected versions should prioritize patching this vulnerability to prevent unauthorized access to sensitive information.
As of now, this vulnerability is included in the Known Exploited Vulnerabilities (KEV) catalog, highlighting its significance in real-world scenarios. Organizations are advised to patch immediately to mitigate risks associated with this vulnerability.
Organizations should also consider implementing additional security measures, such as monitoring email content for unusual patterns and educating users on the dangers of clicking on suspicious links.
Vulnerability Details
The official description of CVE-2023-43770 notes that Roundcube versions before 1.4.14, 1.5.x before 1.5.4, and 1.6.x before 1.6.3 are susceptible to XSS through crafted links in plain text emails. This vulnerability can potentially lead to information disclosure.
With a CVSS base score of 6.1, this vulnerability falls into the medium severity category. Low attack complexity and no privileges required enhance the risk, while user interaction is necessary to trigger the attack.
The affected products include the Roundcube webmail application and Debian Linux version 10.0. The vulnerability was published on September 22, 2023, and is classified under CWE-79.
Technical Analysis
The root cause of CVE-2023-43770 is the improper handling of link references in plain text emails by the rcube_string_replacer.php script. This misimplementation allows attackers to inject malicious scripts via crafted links.
The attack vector is network-based, requiring attackers to send specially crafted emails to potential victims. The complexity of the attack is low, as it does not require advanced skills to exploit. No privileges are needed from the attacker, and user interaction is essential since the victim must open the email for the attack to succeed.
In terms of impact, confidentiality and integrity are affected at a low level, while availability remains unaffected. This means the exploitation could lead to unauthorized access to user data but will not disrupt service availability.
Risk & Impact Analysis
Organizations utilizing vulnerable versions of Roundcube Webmail face significant risks. The ability to exploit this XSS vulnerability poses a threat to sensitive information through unauthorized access. The blast radius can be considerable if exploited on a large scale, potentially affecting numerous users.
Given the high EPSS score of approximately 0.7746, there is a 98.98% chance of exploitation in the wild. Organizations must address this vulnerability in their patch cycles to mitigate associated risks effectively.
The urgency for remediation is classified as critical, and organizations should prioritize patching immediately.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | Yes |
Public PoC | Yes |
Actively Exploited | Yes |
Ransomware Use | No |
Affected Versions
The affected versions of Roundcube include all versions prior to 1.4.14, as well as 1.5.x before 1.5.4 and 1.6.x before 1.6.3. Additionally, Debian Linux version 10.0 is vulnerable.
Mitigation & Remediation
Organizations are strongly advised to update to the latest version of Roundcube to mitigate this vulnerability. For those unable to patch immediately, consider implementing email filtering measures and educating users about the risks of clicking on unknown links.
To enhance security, organizations can also implement monitoring solutions that track user interactions with emails and raise alerts for suspicious activities.
For detailed guidance on security testing, organizations can refer to our penetration testing services.
Detection Guidance
Organizations should monitor logs for unusual patterns indicating exploitation attempts, such as repeated access to known vulnerable links or anomalies in email traffic.
Behavioral anomalies, such as unexpected user actions following the opening of crafted emails, should also be investigated.
Network signatures can be established to alert security teams to suspicious activities associated with this vulnerability.
AppSecure Threat Intelligence Insight
The emergence of CVE-2023-43770 reflects ongoing trends in XSS vulnerabilities, particularly in webmail applications. Organizations must recognize the persistent nature of these vulnerabilities and the risk they pose to user data.
This incident serves as a reminder for organizations to prioritize application security and consider regular audits of their web applications.
For further insights on vulnerability management, organizations can explore our vulnerability management program design.
Additionally, our article on penetration testing methodology provides valuable information on assessing application vulnerabilities.
Finally, organizations should consider participating in regular security assessments to adapt to emerging threats, as discussed in our API security best practices guide.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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