Threat Intelligence / CVE / CVE-2024-42009

CVE-2024-42009 — Roundcube Webmail

CISA KEV
CVSS v3.1 9.3 (CRITICAL) · EPSS 83.3% (higher than 99.6% of all scored CVEs) · Priority 9/10 · Published 2024-08-05

As of 2025-10-21, CVE-2024-42009 is a CRITICAL-severity vulnerability in Roundcube Webmail, CVSS v3.1 9.3, EPSS 83.3% (99.6th percentile). It is listed in the CISA Known Exploited Vulnerabilities catalog (added 2025-06-09), with a US federal remediation deadline of 2025-06-30. Threadlinqs Intelligence links 2 tracked threat campaigns to CVE-2024-42009, most recently “UNK_MassTraction: China-Aligned Actor Exploits Roundcube CVE-2024-42009 & CVE-2025-49113 to Deploy IceCube Stealer and VShell Against University Physics Departments”.

Last updated: 2025-10-21

What is 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 crafted e-mail message that abuses a Desanitization issue in message_body() in program/actions/mail/show.php.

The record classifies CVE-2024-42009 under weakness class CWE-79. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs a user to take an action first, and has high impact on confidentiality, integrity. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 769 days ago.

Severity and exploitation probability

CVSS v3.1 base score
9.3 — CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N
EPSS (FIRST)
83.3% probability of exploitation in the next 30 days, higher than 99.6% of all scored CVEs
CISA KEV
Listed since 2025-06-09, federal remediation deadline 2025-06-30
Threadlinqs priority
9/10 — CISA KEV-listed, which Threadlinqs floors at 9
Published
2024-08-05, last modified 2025-10-21

Is CVE-2024-42009 being exploited?

CISA added CVE-2024-42009 to the Known Exploited Vulnerabilities catalog on 2025-06-09, which means the agency holds evidence of exploitation in the wild; US federal civilian agencies had to remediate it by 2025-06-30 under BOD 22-01. Weaponised exploit code for CVE-2024-42009 is publicly available. 7 public proof-of-concept repositories are tracked for this identifier. A ProjectDiscovery Nuclei detection template exists (http/cves/2024/CVE-2024-42009.yaml). It currently carries a trending score of 45 in the Threadlinqs vulnerability feed.

Affected products and versions

How to fix CVE-2024-42009

Vendor advisory: https://roundcube.net/news/2024/08/04/security-updates-1.6.8-and-1.5.8. Because CVE-2024-42009 is KEV-listed, US federal civilian agencies were required to apply the vendor fix, or stop using the product, by 2025-06-30. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.

Threat activity tracking CVE-2024-42009

2 tracked threats in the Threadlinqs corpus reference CVE-2024-42009, either in the campaign’s CVE list or as an indicator on the campaign record.

Sources

Enriched from CVE.org, NVD, FIRST EPSS, CISA KEV, GitHub Security Advisories, public proof-of-concept repositories, ProjectDiscovery Nuclei. Last verified by Threadlinqs on . This product uses the NVD API but is not endorsed or certified by the NVD.

Other references

Full detection coverage & IOCs for threats exploiting CVE-2024-42009 are available via the Threadlinqs MCP server (Purple tier). View plans →

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