CyberSecBulletin
CVE-2024-20455NVD status: Analyzed

A vulnerability in the process that classifies traffic that is going to the Unified Threat…

Published Updated By the CyberSecBulletin desk

CVE-2024-20455 is a high-severity vulnerability in Cisco IOS XE Software from Cisco, with a CVSS 3.1 base score of 8.6 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Cisco IOS XE Software versions: 17.1.1; 17.1.1a; 17.1.1s, 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 0.66% chance of exploitation within 30 days, higher than 52% 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 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.
  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 IOS XE Software17.1.1; 17.1.1a; 17.1.1s; 17.1.1t; 17.1.3; 17.2.1; 17.2.1r; 17.2.1a; and 32 more rangesNot stated
CiscoCisco IOS XE Catalyst SD-WAN17.5.1a; 17.6.1a; 17.6.2; 17.6.4; 17.7.1a; 17.9.1a; 17.9.2a; 17.9.3a; and 6 more rangesNot stated
Ciscoios_xe17.1.1; 17.1.1a; 17.1.1s; 17.1.1t; 17.1.3; 17.2.1; 17.2.1r; 17.2.1a; and 32 more rangesNot stated
Ciscoios_xe_catalyst_sd-wan17.5.1a; 17.6.1a; 17.6.2; 17.6.4; 17.7.1a; 17.9.1a; 17.9.2a; 17.9.3a; and 6 more rangesNot stated
CiscoiOS Xe Sd-wan17.5.1a; 17.6.1a; 17.6.2; 17.6.4; 17.7.1a; 17.8.1a; 17.9.1a; 17.9.2a; and 6 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
NoneNo account or login is needed.
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:N/UI:N/S:C/C:N/I:N/A:H. Scored by NVD.

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

Official description

A vulnerability in the process that classifies traffic that is going to the Unified Threat Defense (UTD) component of Cisco IOS XE Software in controller mode could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability exists because UTD improperly handles certain packets as those packets egress an SD-WAN IPsec tunnel. An attacker could exploit this vulnerability by sending crafted traffic through an SD-WAN IPsec tunnel that is configured on an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition. Note: SD-WAN tunnels that are configured with Generic Routing Encapsulation (GRE) are not affected by this vulnerability.

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

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 XE Software

All Cisco IOS XE Software vulnerabilities

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