Cisco has issued a security warning about a newly identified vulnerability in its IOS XR Software. This security flaw, labeled CVE-2025-20138, has been rated 8.8 on the CVSS scale, meaning it poses a major risk to affected devices.
What Is the Problem?
The issue is found in the Command Line Interface (CLI) of Cisco’s IOS XR Software. If an attacker gains access to a system with limited user privileges, they can exploit this weakness to execute commands with the highest level of control. This would allow them to make major modifications to the system, potentially leading to severe security threats.
The root of the problem is improper validation of user inputs in certain CLI commands. Because the system does not correctly filter these inputs, attackers can manipulate it using carefully crafted commands. If successful, they can obtain full administrative access, giving them total control over the device.
Who Is Affected?
This vulnerability affects all configurations of Cisco IOS XR 64-bit Software. Users should check Cisco’s official security advisory to confirm if their specific version is vulnerable.
However, some Cisco software versions are confirmed to be unaffected, including:
IOS Software
IOS XE Software
IOS XR 32-bit Software
NX-OS Software
No Quick Fixes—Users Must Update Their Software
Cisco has stated that there are no temporary solutions or workarounds for this security flaw. The only way to protect affected systems is to install the latest software updates provided by Cisco.
The company has outlined which versions require updates:
1. Users running Cisco IOS XR Software Release 24.1 or earlier need to switch to a patched version.
2. Those using Release 24.2 should upgrade to version 24.2.21 when it becomes available.
3. Users on Release 24.3 must transition to a secure version.
Release 24.4 is not affected by this issue.
As of now, there have been no reports of hackers exploiting this flaw. However, because of the severity of the issue, users should not delay in updating their devices.
Cisco is urging all users running affected versions of IOS XR Software to review the security advisory and apply the necessary updates as soon as possible. Keeping software up to date is the only way to ensure systems remain protected from potential cyber threats.
