CVE-2021-1410
📋 TL;DR
This vulnerability allows authenticated remote attackers within an organization to modify other users' distribution lists in Cisco Webex Meetings. It affects organizations using vulnerable versions of Cisco Webex Meetings where users have distribution list functionality enabled. The issue stems from insufficient authorization checks when updating distribution lists.
💻 Affected Systems
- Cisco Webex Meetings
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
An attacker could modify critical distribution lists used for important communications, potentially disrupting business operations or redirecting sensitive communications.
Likely Case
An attacker modifies distribution lists to add/remove members, potentially gaining access to restricted communications or disrupting team collaboration.
If Mitigated
With proper access controls and monitoring, impact is limited to minor disruption of distribution list management.
🎯 Exploit Status
Exploitation requires authenticated access and knowledge of distribution list IDs.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Update to latest version as specified in Cisco advisory
Vendor Advisory: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-webex-distupd-N87eB6Z3
Restart Required: No
Instructions:
1. Log into Cisco Webex administration portal
2. Navigate to system updates section
3. Apply the latest security update
4. Verify update completion in system status
🧯 If You Can't Patch
- Restrict distribution list creation/modification permissions to administrators only
- Implement additional monitoring for distribution list modification activities
🔍 How to Verify
Check if Vulnerable:
Check Webex Meetings version against Cisco advisory; versions prior to fixed release are vulnerableCheck Version:
Check version in Webex Meetings admin portal under System InformationVerify Fix Applied:
Verify Webex Meetings version matches or exceeds the patched version specified in Cisco advisory📡 Detection & Monitoring
Log Indicators:
- Unusual distribution list modification patterns
- Distribution list updates from unexpected users
- Multiple distribution list modifications in short timeframes
Network Indicators:
- HTTP POST requests to distribution list update endpoints with modified parameters
SIEM Query:
webex AND (distribution_list OR distlist) AND (modify OR update OR edit) AND NOT user=authorized_user