CVE-2025-20291
📋 TL;DR
This vulnerability allowed unauthenticated remote attackers to redirect Cisco Webex Meetings users to malicious websites through specially crafted meeting-join URLs. Attackers could exploit insufficient URL validation to conduct phishing attacks by making users believe they were visiting trusted Webex sites. All users of the affected Cisco Webex Meetings service were potentially vulnerable before Cisco addressed the issue.
💻 Affected Systems
- Cisco Webex Meetings
📦 What is this software?
⚠️ 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
Users redirected to sophisticated phishing sites that steal credentials, install malware, or trick users into performing harmful actions while believing they're on legitimate Webex platforms.
Likely Case
Users redirected to credential harvesting pages or malicious sites for phishing campaigns, potentially leading to account compromise or malware infection.
If Mitigated
Minimal impact as Cisco has already patched the service-side vulnerability; users simply need to ensure they're using the updated service.
🎯 Exploit Status
Exploitation required crafting malicious meeting-join URLs but didn't require authentication. The vulnerability has been fixed by Cisco at the service level.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Service-side fix implemented by Cisco
Vendor Advisory: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-webex-urlredirect-uK8dDJSZ
Restart Required: No
Instructions:
No customer action required. Cisco has already addressed the vulnerability in their Webex Meetings service infrastructure. Ensure you're using the latest Webex client versions as general best practice.
🔧 Temporary Workarounds
User awareness training
allEducate users to be cautious of unexpected meeting links and verify URLs before clicking
URL filtering
allImplement web filtering to block known malicious domains and suspicious redirect patterns
🧯 If You Can't Patch
- Monitor for suspicious meeting invitations containing unusual URLs or unexpected meeting links
- Implement browser security extensions that warn about URL redirects and suspicious domains
🔍 How to Verify
Check if Vulnerable:
Check if you're using Cisco Webex Meetings service - the vulnerability was service-side and has been fixed by CiscoCheck Version:
Not applicable - service-side fix already implementedVerify Fix Applied:
The fix is implemented at Cisco's service level. No customer verification needed as per Cisco's advisory📡 Detection & Monitoring
Log Indicators:
- Unusual meeting join patterns, multiple redirects from Webex URLs, suspicious URL parameters in meeting links
Network Indicators:
- HTTP redirects from Webex domains to unexpected external domains, unusual traffic patterns following meeting joins
SIEM Query:
web.url contains "webex.com" AND web.url contains suspicious redirect parameters OR destination.domain not in (trusted_domains)