CVE-2023-43770
Roundcube Webmail Persistent Cross-Site Scripting (XSS) Vulnerability
Roundcube Webmail
Roundcube before 1.4.14, 1.5.x before 1.5.4, and 1.6.x before 1.6.3 allows XSS via text/plain e-mail messages with crafted links because of program/lib/Roundcube/rcube_string_replacer.php behavior.
Exploitation status
CISA Known Exploited Vulnerabilities
Listed by CISA on 12 February 2024. US federal agencies were required to remediate it by 4 March 2024.
EPSS — exploitation probability
FIRST puts the probability of exploitation activity in the next 30 days at 63.7%, which is higher than 99.2% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Frequently asked questions
Is CVE-2023-43770 being exploited by ransomware groups?
No ransomware group in this database is currently recorded as exploiting CVE-2023-43770.
What does CVE-2023-43770 affect?
CVE-2023-43770 affects Roundcube Webmail. Roundcube before 1.4.14, 1.5.x before 1.5.4, and 1.6.x before 1.6.3 allows XSS via text/plain e-mail messages with crafted links because of program/lib/Roundcube/rcube_string_replacer.php behavior.
How severe is CVE-2023-43770?
CVE-2023-43770 is rated MEDIUM with a CVSS base score of 6.1. EPSS puts the probability of exploitation in the next 30 days at 63.7%, higher than 99.2% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 4 March 2024.
How should organisations respond to CVE-2023-43770?
Apply the vendor patch for Roundcube Webmail as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.