CVE-2025-20141
📋 TL;DR
An unauthenticated adjacent attacker can send specially crafted packets to Cisco IOS XR devices, causing control plane traffic to stop working. This affects Cisco IOS XR Software Release 7.9.2 on multiple platforms, resulting in a denial of service condition.
💻 Affected Systems
- Cisco IOS XR Software
📦 What is this software?
Ios Xr by Cisco
⚠️ Risk & Real-World Impact
Worst Case
Complete control plane failure leading to network-wide outages, loss of routing protocols, and inability to manage affected devices.
Likely Case
Localized denial of service affecting specific network segments where attacker has adjacent access, disrupting routing and management traffic.
If Mitigated
Minimal impact if proper network segmentation and access controls prevent adjacent attackers from reaching vulnerable interfaces.
🎯 Exploit Status
Exploitation requires sending specific traffic that triggers the vulnerable packet handling path. Attacker must be adjacent to the target device.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Upgrade to a fixed release (consult Cisco advisory for specific versions)
Vendor Advisory: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-xr792-bWfVDPY
Restart Required: No
Instructions:
1. Review Cisco Security Advisory for fixed software versions. 2. Download appropriate software from Cisco.com. 3. Upgrade affected devices following standard IOS XR upgrade procedures. 4. Verify the upgrade was successful.
🔧 Temporary Workarounds
Implement Access Control Lists
allRestrict traffic to route processor from untrusted sources to prevent exploitation
configure terminal
ipv4 access-list RP-PROTECTION
deny ip any any
commit
Network Segmentation
allIsolate management and control plane traffic from user/data traffic
🧯 If You Can't Patch
- Implement strict network segmentation to limit adjacent access to vulnerable devices
- Deploy intrusion prevention systems to detect and block exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check software version with 'show version' command and verify if running IOS XR Release 7.9.2Check Version:
show version | include Cisco IOS XR SoftwareVerify Fix Applied:
After upgrade, verify version no longer shows 7.9.2 and check for successful commit of any workaround configurations📡 Detection & Monitoring
Log Indicators:
- Route processor CPU spikes
- Control plane protocol failures
- Punted packet rate anomalies
Network Indicators:
- Unusual traffic patterns targeting route processor interfaces
- BGP/OSPF session flaps
- Management connectivity loss
SIEM Query:
source="ios-xr" AND ("punted" OR "route processor" OR "control plane") AND severity>=warning