cbcvebase.
CVE-2024-42009
published 2024-08-05

CVE-2024-42009: 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…

PriorityP186critical9.3CVSS 3.1
AVNACLPRNUIRSCCHIHAN
KEVITWEXPLOITInitial access
CISA Known Exploited Vulnerabilitydue 2025-06-30
Exploited in the wild
EPSS
82.88%
99.6th percentile
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 message_body() in program/actions/mail/show.php.

Affected

3 ranges
VendorProductVersion rangeFixed in
debianroundcube< roundcube 1.6.5+dfsg-1+deb12u3 (bookworm)roundcube 1.6.5+dfsg-1+deb12u3 (bookworm)
roundcubewebmail< 1.5.81.5.8
roundcubewebmail>= 1.6.0 < 1.6.81.6.8

Detection & IOCsextracted from sources · hover to see the quote

pathprogram/actions/mail/show.php
  • Nuclei template fingerprints vulnerable Roundcube instances by extracting the rcversion JSON field from the base URL response and matching versions <= 1.6.7 or = 1.6.0, combined with the word 'Roundcube' in the body and HTTP 200 status.
  • Shodan query to identify exposed Roundcube webmail instances susceptible to CVE-2024-42009.
  • FOFA query to identify Roundcube instances via session cookie name.
  • Post-exploitation web shell SquareShell is deployed in memory at the Roundcube newmail_notifier plugin path; monitor for unexpected PHP execution or HTTP requests to that endpoint.
  • IceCube JavaScript payload exfiltrates credentials, 2FA tokens, and cookies via HTTP POST to an external C2; monitor for anomalous POST requests originating from Roundcube webmail sessions.
  • IceCube leverages the session's CSRF token to chain exploitation of a second RCE vulnerability (CVE-2025-49113); monitor for CSRF token reuse in unexpected POST requests within Roundcube sessions.
  • Upon compromise, IceCube destroys server-side sessions to erase forensic evidence; monitor for abnormal mass session invalidation events on Roundcube servers.
  • The attack only requires the victim to open the email in Roundcube; no further user interaction is needed. Alert on any Roundcube versions <= 1.5.7 or 1.6.0–1.6.7 receiving external emails with complex HTML/script content.
  • SNOWLIGHT ELF loader is fetched and executed via a shell script dropped through the Roundcube vulnerability as a fallback when SquareShell web shell deployment fails; monitor for ELF binary downloads initiated from web server processes.
  • Threat actor UNK_MassTraction used both compromised sender accounts and domains with lax DMARC policies for spoofing; monitor for Roundcube-targeted emails from domains failing DMARC checks.
  • ·The XSS vulnerability exists in Roundcube versions through 1.5.7 and 1.6.x through 1.6.7; versions 1.5.8 and 1.6.8+ are patched.
  • ·The vulnerable code path is specifically in the message_body() function within program/actions/mail/show.php; patch validation should confirm this function is sanitized.
  • ·CISA mandated remediation by 2025-06-30 for federal agencies; organizations should apply vendor patches from https://roundcube.net/news/2024/08/04/security-updates-1.6.8-and-1.5.8
  • ·Debian stable (bookworm) fix is in 1.6.5+dfsg-1+deb12u3; bullseye fix is in 1.4.15+dfsg.1-1+deb11u4. Operators on Debian should verify their package version matches or exceeds these.

CVSS provenance

nvdv3.19.3CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N
osv9.3CRITICAL
vulncheck9.3CRITICAL
cisa9.3CRITICAL
vendor_debian9.3CRITICAL
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