dbcve.org
Information ExposureWeakness · CWE-200

CVE-2024-42010

HIGH · 7.5 CVSS v3.1 Published 2024-08-05
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
High EPSS Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Roundcube's mod_css_styles component fails to properly filter CSS token sequences in email message rendering, allowing malicious CSS to be embedded in emails that can exfiltrate sensitive information such as session tokens, credentials, or other data through CSS-based attacks.

MitigationUpgrade Roundcube to version 1.5.8 or 1.6.8 or later where proper CSS filtering is implemented. Consider disabling external stylesheets in email rendering as an interim measure.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed Roundcube version
    Check the Roundcube version file (such as program/include/iniset.php or the version constant) or view the footer of the Roundcube login page which often displays the version number
    Affected if The installed version is earlier than 1.5.8 in the 1.5.x series OR earlier than 1.6.8 in the 1.6.x series (for example, 1.5.0-1.5.7 or 1.6.0-1.6.7)
  2. Verify mod_css_styles plugin is active
    Locate the Roundcube plugins configuration file (typically config/main.inc.php or config/config.inc.php) and check if mod_css_styles is listed among the enabled plugins in the $rcmail_config['plugins'] array
    Affected if The mod_css_styles plugin is enabled in the Roundcube configuration
  3. Confirm CSS processing for email rendering is enabled
    Check the Roundcube main configuration file for settings related to CSS processing in emails, such as $rcmail_config['css_styles'] or similar CSS-related configuration options that control how styles are processed when rendering messages
    Affected if CSS processing for email messages is enabled in the Roundcube configuration (any setting that allows incoming email CSS to be parsed and applied)
  4. Inspect email CSS filtering configuration
    Look for configuration options that control CSS sanitization or filtering in the Roundcube config directory, particularly those related to the mod_css_styles component or email message styling
    Affected if There is no explicit CSS filtering or sanitization configured, or the filtering is set to allow unfiltered CSS from external or embedded sources

You are affected if your Roundcube version is before 1.5.8 or 1.6.8 AND the mod_css_styles plugin is enabled with CSS processing active for email rendering without proper filtering enabled.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade Roundcube to version 1.5.8 or 1.6.8 or later where proper CSS filtering is implemented. Consider disabling external stylesheets in email rendering as an interim measure.

Recommended fix High confidence

Roundcube 1.5.8 (for 1.5.x users) or Roundcube 1.6.8 (for 1.6.x users)

  1. 1. Identify current Roundcube version by checking the version file or changelog
  2. 2. Create a complete backup of the Roundcube installation directory and database
  3. 3. Download the fixed release (1.5.8 for the 1.5.x branch or 1.6.8 for the 1.6.x branch) from the official Roundcube repository
  4. 4. Extract the new version over the existing installation, preserving local configuration
  5. 5. Clear any cached templates and temporary files in the tmp/ and cache/ directories
  6. 6. Verify the upgrade was successful by checking the About page shows the new version number
Caveat Minor version upgrades in Roundcube are typically backward-compatible; review the release notes for any configuration changes

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
9.0 hours of engineering $1,570
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2024-42010 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data