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Mallory
MediumCISA KEVExploited in the wildPublic exploit

Stored XSS in Roundcube Webmail via SVG animate attributes

IdentifiersCVE-2024-37383CWE-79· Improper Neutralization of Input…

CVE-2024-37383 is a stored cross-site scripting vulnerability in Roundcube Webmail caused by improper processing of SVG animate attributes in email content. It affects Roundcube Webmail before 1.5.7 and 1.6.x before 1.6.7. A remote attacker can send a specially crafted email containing malicious SVG content, including animate-tag based payloads, that bypasses expected syntax checks and executes attacker-controlled JavaScript when the victim opens the message in Roundcube. Reporting on observed exploitation indicates the payload can be embedded in content processed by the client but not visibly rendered to the user, enabling stealthy execution in the security context of the victim’s Roundcube session.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation allows execution of arbitrary JavaScript in the victim’s browser within the context of the Roundcube webmail application. In observed campaigns, this was used to inject fake Roundcube login forms for credential theft, access sensitive mail-related data, and abuse available functionality such as retrieving messages and manipulating mail settings. The vulnerability has been used in phishing and espionage-oriented campaigns and has been reported as actively exploited in the wild, including inclusion in CISA’s KEV catalog.

Mitigation

If you can’t patch tonight, do this now.

If immediate patching is not possible, reduce exposure by restricting access to Roundcube where feasible, filtering or sanitizing inbound email content containing SVG elements or animate attributes, and monitoring for suspicious JavaScript execution or anomalous requests originating from Roundcube sessions. Administrators should inspect for unauthorized login prompts, unexpected credential collection behavior, malicious or recently delivered crafted emails, and abuse of plugins or mail-filter functionality such as ManageSieve. Users should be warned not to trust unexpected login prompts appearing inside an opened email message.

Remediation

Patch, then assume compromise.

Upgrade Roundcube Webmail to a fixed release: 1.5.7 or later on the 1.5 branch, or 1.6.7 or later on the 1.6 branch. More generally, ensure deployments are updated beyond all vulnerable versions identified as before 1.5.7 and 1.6.x before 1.6.7. Because exploitation has been observed in the wild, patching should be prioritized and any exposed or internet-accessible Roundcube instances should be reviewed for signs of compromise, suspicious emails containing SVG content, credential theft activity, and unauthorized mail-forwarding or sieve-rule changes.
PUBLIC EXPLOITS

Exploits

3 valid exploits after Mallory filtered fakes, detection scripts, and README-only repos (1 hidden).

VALID 3 / 4 TOTALView more in app
CVE-2024-37383_PoCMaturityPoCVerified exploit

Repository is a small PoC/lab for CVE-2024-37383 (Roundcube Webmail SVG parsing XSS). Structure: (1) docker-compose.yml spins up a vulnerable Roundcube instance (roundcube/roundcubemail:1.6.6-apache) and a GreenMail standalone server providing SMTP/IMAP and a web UI. Roundcube is exposed on host port 8080; GreenMail exposes 3000 (web/API), 3143 (IMAP), 3025 (SMTP). (2) send.py is the exploit driver: it connects to SMTP at localhost:3025 and sends an email from/to test@example.com containing a multipart message with a crafted HTML part. The HTML embeds an <svg> with an <animate> element using a malformed attributeName ("href ") and a javascript: URL in values, intended to trigger XSS when the email is viewed in Roundcube. README.md documents affected versions (v1.5.7 and v1.6.x < v1.6.7), setup steps, and links to an analysis report. Overall purpose: provide a reproducible local environment and a minimal script to deliver the malicious email demonstrating the XSS.

hyungin0505Disclosed Feb 14, 2026pythonyamlnetwork (SMTP delivery of malicious HTML email leading to client-side XSS in webmail UI)
CVE-2024-37383-exploitMaturityPoCVerified exploit

This repository contains an operational exploit for CVE-2024-37383, a stored XSS vulnerability in Roundcube Webmail (versions earlier than 1.5.6 and 1.6-1.6.6). The exploit consists of a JavaScript file ('Roundcube_mail_server_exploit_for_CVE-2024-37383.js') and a detailed README. The JavaScript payload is designed to be injected via a crafted email (e.g., using an SVG <animate> tag) and, when executed in the victim's browser, will enumerate all inbox messages, extract their titles and contents, and send them to an attacker-controlled server via POST requests. The README provides step-by-step instructions for configuring the exploit, including setting the target Roundcube instance and the attacker's server endpoint. The exploit is not part of a framework and is a standalone script. The main attack vector is browser-based XSS, requiring the victim to open a malicious email in a vulnerable Roundcube instance. The repository is well-structured, with clear separation between documentation and exploit code.

amirzarghamDisclosed Nov 3, 2024javascriptmarkdownbrowser
CVE-2024-37383-POCMaturityPoCVerified exploit

This repository is a proof-of-concept (POC) exploit for CVE-2024-37383, a stored XSS vulnerability in Roundcube Webmail. The repository contains three files: a README.md with usage instructions, exploit.py (the main exploit script), and start_roudcube.sh (a helper script to launch a local Roundcube instance via Docker). The exploit works by sending a specially crafted HTML email containing an SVG element with an <animate> tag that, when clicked by the victim in the Roundcube webmail interface, triggers a JavaScript alert. The exploit.py script allows the attacker to specify sender and recipient email addresses, SMTP host, and port, making it flexible for different email providers. The start_roudcube.sh script sets up a vulnerable Roundcube instance for testing, using GMX as the default mail provider. The main attack vector is network-based (sending email) and browser-based (victim interaction with the webmail UI). The exploit demonstrates the vulnerability but requires user interaction (clicking the link) to trigger the XSS payload.

bartfroklageDisclosed Oct 24, 2024pythonbashnetworkbrowser
EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType
DebianDebian Linuxoperating_system
RoundcubeWebmailapplication

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What this page doesn’t show

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Threat actor evidence1

Every observed campaign linking this CVE to a named adversary.

Associated malware

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Detection signatures1

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Vendor-by-vendor mapping

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Social activity1

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