CVE-2025-27823
📋 TL;DR
The Mail Disguise module for Backdrop CMS before version 1.x-1.0.5 has a cross-site scripting (XSS) vulnerability due to insufficient validation of data attributes in link elements. Attackers who can insert malicious HTML links can execute arbitrary JavaScript in victims' browsers. This affects Backdrop CMS websites using the vulnerable Mail Disguise module.
💻 Affected Systems
- Backdrop CMS Mail Disguise module
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
An attacker could steal session cookies, perform actions as authenticated users, deface websites, or redirect users to malicious sites.
Likely Case
Attackers with content creation privileges could inject malicious scripts affecting visitors, potentially stealing credentials or session data.
If Mitigated
With proper input validation and output encoding, the risk is limited to authenticated users with specific permissions.
🎯 Exploit Status
Exploitation requires authenticated access with content creation/edit permissions. No public exploit code is known at this time.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.x-1.0.5
Vendor Advisory: https://backdropcms.org/security/backdrop-sa-contrib-2025-007
Restart Required: No
Instructions:
1. Update the Mail Disguise module to version 1.x-1.0.5 or later via the Backdrop CMS admin interface or manually. 2. Clear all caches after updating.
🔧 Temporary Workarounds
Disable Mail Disguise module
allTemporarily disable the vulnerable module until patching is possible
Restrict content creation permissions
allLimit who can create/edit content with HTML to trusted users only
🧯 If You Can't Patch
- Disable the Mail Disguise module entirely
- Implement strict content review processes for all HTML content
🔍 How to Verify
Check if Vulnerable:
Check the Mail Disguise module version in Backdrop CMS admin at Structure > Modules or via the database in the system table.Check Version:
SELECT name, info FROM system WHERE name = 'mail_disguise';Verify Fix Applied:
Confirm the Mail Disguise module version is 1.x-1.0.5 or higher in the module administration page.📡 Detection & Monitoring
Log Indicators:
- Unusual content edits with HTML link elements containing data attributes
- Multiple failed XSS attempts in web server logs
Network Indicators:
- Suspicious JavaScript execution patterns in browser traffic
SIEM Query:
source="web_server" AND (message="*data-*" OR message="*<a*data-*")