Cisco IOS XE Software: Improper Check for Unusual or Exceptional Conditions
CVE-2025-20198 is a high-severity improper check for unusual or exceptional conditions vulnerability in Cisco IOS XE Software from Cisco, with a CVSS 3.1 base score of 8.2 out of 10. It can be exploited with local access to the system by an attacker with administrator privileges, 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 0.17% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of Cisco IOS XE Software you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on sec.cloudapps.cisco.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Cisco | Cisco IOS XE Software | 3.13.0S; 3.13.1S; 3.13.2S; 3.13.3S; 3.13.4S; 3.13.5S; 3.13.2aS; 3.13.0aS; and 32 more ranges | Not stated |
| Cisco | iOS Xe | 3.7.0e; 3.7.1e; 3.7.2e; 3.7.3e; 3.7.4e; 3.7.5e; 3.8.0e; 3.8.1e; and 32 more ranges | Not 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
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- HighAdministrator-level access is required first.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 4.6 | Medium | CNA (cisco.com) |
| CVSS 3.1 | 8.2 | High | NVD |
Official description
A vulnerability in the CLI of Cisco IOS XE Software could allow an authenticated, local attacker with privilege level 15 to elevate privileges to root on the underlying operating system of an affected device. This vulnerability is due to insufficient input validation when processing specific configuration commands. An attacker could exploit this vulnerability by including crafted input in specific configuration commands. A successful exploit could allow the attacker to elevate privileges to root on the underlying operating system of an affected device. The security impact rating (SIR) of this advisory has been raised to High because an attacker could gain access to the underlying operating system of the affected device and perform potentially undetected actions. Note: The attacker must have privileges to enter configuration mode on the affected device. This is usually referred to as privilege level 15.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Check for Unusual or Exceptional Conditions
The product does not check or incorrectly checks for unusual or exceptional conditions that are not expected to occur frequently during day to day operation of the product.
How developers prevent this class of flaw
- Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Choose languages with features such as exception handling that force the programmer to anticipate unusual conditions that may generate exceptions. Custom exceptions may need to be developed to handle unusual business-logic conditions. Be careful not to pass sensitive exceptions back to the user (CWE-209, CWE-248).
- Check the results of all functions that return a value and verify that the value is expected.
- If using exception handling, catch and throw specific exceptions instead of overly-general exceptions (CWE-396, CWE-397). Catch and handle exceptions as locally as possible so that exceptions do not propagate too far up the call stack (CWE-705). Avoid unchecked or uncaught exceptions where feasible (CWE-248).
More Improper Check for Unusual or Exceptional Conditions vulnerabilities (CWE-754)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other vulnerabilities in Cisco IOS XE Software
- 8.6 High severity
- 8.6 High severity
- 9.8 Critical severity
- 8.6 High severity
- 8.6 High severity
- 8.6 High severity
Recent Improper Check for Unusual or Exceptional Conditions vulnerabilities
- 8.2 High severity
- 8.1 High severity
- 9.3 Critical severity
- 8.7 High severity
- 7.5 High severity
- 7.5 High severity
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