Cyber Resilience

CVE-2024-42010

High

Published: 05 August 2024

Published
05 August 2024
Modified
15 April 2026
KEV Added
Patch
CVSS Score v3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS Score 0.1509 94.7th percentile
Risk Priority 24 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2024-42010 is a high-severity Exposure of Sensitive Information to an Unauthorized Actor (CWE-200) vulnerability in Roundcube (inferred from references). Its CVSS base score is 7.5 (High).

Operationally, ranked in the top 5.3% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

Deeper analysis

CVE-2024-42010 affects the mod_css_styles component in Roundcube webmail versions through 1.5.7 and 1.6.x through 1.6.7. The flaw stems from insufficient filtering of Cascading Style Sheets token sequences when rendering email messages, which can expose sensitive information to unauthorized actors as classified under CWE-200. The vulnerability carries a CVSS 3.1 score of 7.5 reflecting network attack vector, low complexity, and high confidentiality impact without requiring authentication or user interaction.

A remote attacker can exploit the issue by sending a specially crafted email containing malicious CSS sequences. When the message is rendered by a vulnerable Roundcube instance, the attacker may obtain sensitive data from the recipient's environment or session.

Official patches are available in Roundcube 1.5.8 and 1.6.8, as detailed in the project's release notes and security advisory published on 4 August 2024. Administrators are advised to upgrade promptly to address the filtering deficiency in CSS handling.

The EPSS score has reached a peak of 0.1725 with a current value of 0.1509, indicating moderate and relatively stable exploitation interest following disclosure. A related SonarSource analysis highlights broader risks to government email systems using the affected webmail software.

EU & UK References

Vulnerability details

mod_css_styles 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.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

Roundcube
inferred from references and description; NVD did not file a CPE for this CVE

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-200

Automated marking applies security attributes to system outputs, making it harder for attackers to exploit unmarked sensitive information leading to unauthorized exposure.

addresses: CWE-200

Proper attribute retention and permitted-value enforcement limits unauthorized actors from accessing sensitive information lacking correct labels.

addresses: CWE-200

Prevents unauthorized exposure of sensitive information by prohibiting untrusted external systems from processing or storing it.

addresses: CWE-200

By enforcing authorization matching prior to sharing, the control reduces the risk of exposing sensitive information to unauthorized actors.

addresses: CWE-200

Review and removal of nonpublic information from publicly accessible systems directly prevents exposure of sensitive data to unauthorized actors.

addresses: CWE-200

Data mining protection mechanisms detect and block unauthorized bulk extraction of sensitive data, directly mitigating exposure to unauthorized actors.

addresses: CWE-200

Literacy training teaches users to recognize and avoid actions that result in unauthorized exposure of sensitive information.

addresses: CWE-200

Retaining and monitoring training records confirms personnel have completed privacy and security awareness training on handling sensitive data, reducing the chance of unauthorized exposure due to lack of knowledge.

References