CyberSecBulletin
CVE-2025-20192NVD status: Analyzed

Cisco IOS XE Software: Improper Handling of Undefined Values

CVE-2025-20192 is a high-severity improper handling of undefined values vulnerability in Cisco IOS XE Software from Cisco, with a CVSS 3.1 base score of 7.7 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected Cisco IOS XE Software versions: 3.13.0S; 3.13.1S; 3.13.2S, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.48% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of Cisco IOS XE Software you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on sec.cloudapps.cisco.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
CiscoCisco IOS XE Software3.13.0S; 3.13.1S; 3.13.2S; 3.13.3S; 3.13.4S; 3.13.5S; 3.13.6S; 3.13.7S; and 32 more rangesNot stated
CiscoiOS Xe3.13.0s; 3.13.1s; 3.13.2s; 3.13.3s; 3.13.4s; 3.13.5s; 3.13.6as; 3.13.6s; and 32 more rangesNot stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
NoneNo data is disclosed.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H. Scored by CNA (cisco.com).

Official description

A vulnerability in the Internet Key Exchange version 1 (IKEv1) implementation of Cisco IOS XE Software could allow an authenticated, remote attacker to cause a denial of service (DoS) condition. The attacker must have valid IKEv1 VPN credentials to exploit this vulnerability. This vulnerability is due to improper validation of IKEv1 phase 2 parameters before the IPsec security association creation request is handed off to the hardware cryptographic accelerator of an affected device. An attacker could exploit this vulnerability by sending crafted IKEv1 messages to the affected device. A successful exploit could allow the attacker to cause the device to reload.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Handling of Undefined Values

The product does not handle or incorrectly handles when a value is not defined or supported for the associated parameter, field, or argument name.

More Improper Handling of Undefined Values vulnerabilities (CWE-232)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Cisco IOS XE Software

All Cisco IOS XE Software vulnerabilities

Recent Improper Handling of Undefined Values vulnerabilities

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