CyberSecBulletin
CVE-2022-20919NVD status: Modified

Cisco IOS: Improper Handling of Exceptional Conditions

CVE-2022-20919 is a high-severity improper handling of exceptional conditions vulnerability in Cisco IOS from Cisco, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. There is no confirmed exploitation so far. EPSS estimates a 1.21% chance of exploitation within 30 days, higher than 69% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of Cisco IOS you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on tools.cisco.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
CiscoCisco IOSNot specified in the recordNot stated
CiscoiOS Xe17.9.1Not 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
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
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:N/UI:N/S:U/C:N/I:N/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.18.6HighCNA (cisco.com)
CVSS 3.17.5HighNVD

Official description

A vulnerability in the processing of malformed Common Industrial Protocol (CIP) packets that are sent to Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to unexpectedly reload, resulting in a denial of service (DoS) condition. This vulnerability is due to insufficient input validation during processing of CIP packets. An attacker could exploit this vulnerability by sending a malformed CIP packet to an affected device. A successful exploit could allow the attacker to cause the affected device to unexpectedly reload, resulting in a DoS condition.

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

The underlying weakness: Improper Handling of Exceptional Conditions

The product does not handle or incorrectly handles an exceptional condition.

More Improper Handling of Exceptional Conditions vulnerabilities (CWE-755)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Cisco IOS

All Cisco IOS vulnerabilities

Recent Improper Handling of Exceptional Conditions vulnerabilities

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