The twofactorgauthenticator plugin for Roundcube is vulnerable to brute-forcing of the second-factor code. Due to the lack of rate limiting, an attacker who obtains user's password can submit arbitrary 6-digit codes, resulting in second-factor bypass and unauthorized access to the system. This issue was fixed in commit 4640889.

The twofactorgauthenticator plugin for Roundcube is vulnerable to session persistence after failed 2FA verification. Due to the lack of server-side session destruction, an attacker can ignore the logout redirect and keep the session alive. This may allow an attacker who obtains user's password to e.g. brute force the second-factor code. This issue was fixed in commit 4640889.

The twofactorgauthenticator plugin for Roundcube is vulnerable to 2fa authentication bypass by spoofed client address headers. Due to the lack of validation of the Client-IP and X-Forwarded-For headers, an attacker who obtains user's password can spoof a whitelisted IP address, resulting in the second factor being bypassed. This issue was fixed in commit 4640889.

In Roundcube Webmail before 1.6.17 and 1.7.x before 1.7.2, insufficient Cascading Style Sheets (CSS) sanitization in HTML e-mail messages may lead to SSRF or Information Disclosure, e.g., if stylesheet links point to local network hosts. NOTE: this issue exists because of insufficient fixes for CVE-2026-35540 and CVE-2026-48843.

Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 is affected by an improper authentication vulnerability in multi-host installations. When a user logs in with an alias address, rcubeuser::query() matched the address against identity records without qualifying the lookup by IMAP host, so a login could be resolved to a user account belonging to a different IMAP host. Upstream fixed this in the commit “Fix bug where an alias login wasn’t qualified by IMAP host”.

Roundcube Webmail 1.6.14 before 1.6.20 and 1.7.0 before 1.7.5 is affected by a server-side request forgery filter bypass. The network blocklist used by rcubeutils::islocalurl() omitted the RFC 6052 NAT64 prefix 64:ff9b::/96, the RFC 8215 local-use NAT64 prefix 64:ff9b:1::/48 and the unspecified address ::/128, so URLs such as http://[64:ff9b::7f00:1]/ passed the filter and reached loopback, link-local and cloud metadata addresses. Upstream fixed this in the commit “Fix SSRF filter (islocalurl()) bypass via NAT64 64:ff9b::/96”.

Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 is affected by a remote content blocking bypass. rcubewashtml inspected the SVG SMIL animation attributes to, from and values for URIs, but not by; so markup such as in an HTML message caused remote content to be loaded without the user's consent, disclosing the client IP address and confirming that the message was opened. Upstream fixed this in the commit “Fix remote-content blocker bypass via SVG SMIL by attribute”.

Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 is affected by an uncontrolled resource consumption vulnerability in the CSS proxy (the utils/modcss action). The fetched stylesheet was read into memory in full, with no size limit and no read timeout, so a stylesheet URL referencing an attacker-controlled host could be used to exhaust server memory. Upstream fixed this in the commit “Add a size limit to the CSS proxy content processing”, which caps the response at 5 MB, reads it as a stream and applies a read timeout.

Roundcube Webmail before 1.5.7 and 1.6.x before 1.6.7 on Windows allows command injection via imconvertpath and imidentifypath. NOTE: this issue exists because of an incomplete fix for CVE-2020-12641.

Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 allows the ImageMagick resource limits to be bypassed during thumbnail generation. When rcubeimage falls back to GD, the available-memory check was applied only on Windows, so on other platforms a crafted image with large dimensions was processed by GD without any resource limit and could exhaust server memory. Upstream fixed this in the commit “Fix ImageMagick resource limits bypass by GD fallback during thumbnail generation”, which applies the memory check on all platforms.

Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 is affected by a CSS scoping bypass in HTML messages. rcubeutils::modcssstyles() did not treat an at-rule prologue such as @layer a; as a selector boundary, and did not handle selectors beginning with ::, so selectors following an at-rule were left unscoped and applied to the whole Roundcube interface instead of being confined to the message body. This allows an HTML message to restyle application chrome for UI redressing and spoofing. Upstream fixed this in the commit “Fix CSS scoping bypass in HTML messages using at-rules”.

Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 is affected by a CSRF validation bypass in the mark-as-junk action of the markasjunk plugin. The plugin read the uid parameter from POST data but passed it to rcmail::getuids() without constraining the input mode, so values re-read inside that helper could be taken from the query string and the action carried out without a valid CSRF token. Upstream fixed this in the commit “Fix CSRF validation bypass in the mark-as-junk action”, which passes rcubeutils::INPUTPOST explicitly.

Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 passes potentially unsafe content into ImageMagick when resizing images. SVG and EPS were accepted as valid image types for contact photo upload and conversion, and both formats can reference external resources and invoke ImageMagick delegates when processed. Upstream fixed this in the commit “Fix passing potentally unsafe attachment content into ImageMagick on image resize”, which removes svg and eps from the accepted types.

Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 is affected by an incorrect authorization vulnerability in the Modoboa driver of the password plugin. The driver took the first entry of the account search result returned by the Modoboa API instead of matching the authenticated user, so a password change could be applied to a different account. Upstream fixed this in the commit “Fix bug where Password Modoboa driver could change password for another account”, which selects the account whose username matches and fails if none does.

Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 is affected by a mail header injection vulnerability when a message is forwarded as an attachment. The subject of the forwarded message was used verbatim to generate the attachment name, so a received message whose subject contains CRLF sequences could inject arbitrary MIME part headers into the outgoing message. Upstream fixed this in the commit “Fix mail header injection via subject of a message forwarded as attachment”, which collapses whitespace in the generated name.

Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 is affected by a cross-site scripting vulnerability in the password plugin. Error text returned by a password driver was concatenated into the message presented to the user without HTML escaping, so a backend able to influence that text, such as the DirectAdmin API, could inject script into the Roundcube interface. Upstream fixed this in the commit “Fix XSS issue in handling of password driver error responses”, which escapes the driver message before display.

Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 allows the disabledactions configuration setting to be bypassed. The check compared only the action name as requested, so a remote authenticated attacker could reach an action listed in disabledactions by requesting it through its deprecated alias instead. Upstream fixed this in the commit “Fix bug where deprecated action aliases bypassed disabledactions setting”, which moves the check into rcmail::actionhandler() and resolves aliases before comparing.

In Roundcube from versions 1.2.0 to 1.3.5, with the archive plugin enabled and configured, it's possible to exploit the unsanitized, user-controlled "uid" parameter (in an archive.php task=mail&mbox=INBOX&action=plugin.move2archive request) to perform an MX (IMAP) injection attack by placing an IMAP command after a %0d%0a sequence. NOTE: this is less easily exploitable in 1.3.4 and later because of a Same Origin Policy protection mechanism.

Roundcube Webmail allows arbitrary password resets by authenticated users. This affects versions before 1.0.11, 1.1.x before 1.1.9, and 1.2.x before 1.2.5. The problem is caused by an improperly restricted exec call in the virtualmin and sasl drivers of the password plugin.

Last updated 13 January 2025

steps/mail/func.inc in Roundcube before 1.3.8 has XSS via crafted use of <svg><style>, as demonstrated by an onload attribute in a BODY element, within an HTML attachment.

Cross-Site Scripting (XSS) vulnerability in Roundcube Webmail 1.6.9 allows remote authenticated users to upload a malicious file as an email attachment, leading to the triggering of the XSS by visiting the SENT session.

modcssstyles in Roundcube through 1.5.7 and 1.6.x through 1.6.7 insufficiently filters Cascading Style Sheets (CSS) token sequences in rendered e-mail messages, allowing a remote attacker to obtain sensitive information.

A Cross-Site Scripting vulnerability in Roundcube through 1.5.7 and 1.6.x through 1.6.7 allows a remote attacker to steal and send emails of a victim via a crafted e-mail message that abuses a Desanitization issue in messagebody() in program/actions/mail/show.php.

A Cross-Site Scripting vulnerability in rcmailactionmailget->run() in Roundcube through 1.5.7 and 1.6.x through 1.6.7 allows a remote attacker to steal and send emails of a victim via a malicious e-mail attachment served with a dangerous Content-Type header.

Last updated 24 July 2024

Last updated 24 July 2024

In Roundcube Webmail before 1.6.18 and 1.7.x before 1.7.3, responses from the CSS (Cascading Style Sheets) proxy were not validated, which may result in information disclosure or XSS (cross-site scripting) via MIME sniffing.

In Roundcube Webmail before 1.6.18 and 1.7.x before 1.7.3, improper HTML/CSS sanitization of the SVG animate "by" attribute may lead to remote image blocking bypass, which in turn may lead to information disclosure or privilege escalation.

In Roundcube Webmail before 1.6.17 and 1.7.x before 1.7.2, the TNEF decoder was subject to denial of service via a crafted compressed-RTF size.