Cisco IOS XE Software: Incomplete Cleanup
CVE-2024-20303 is a high-severity incomplete cleanup vulnerability in Cisco IOS XE Software from Cisco, with a CVSS 3.1 base score of 7.4 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. Affected Cisco IOS XE Software versions: 17.2.1; 17.2.1r; 17.2.1a, 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 0.32% 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 | 17.2.1; 17.2.1r; 17.2.1a; 17.2.1v; 17.2.2; 17.2.3; 17.3.1; 17.3.2; and 32 more ranges | Not stated |
| Cisco | iOS Xe | 17.2.1; 17.2.1a; 17.2.1r; 17.2.1v; 17.2.2; 17.2.3; 17.3.1; 17.3.1a; 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
- AdjacentThe attacker must be on the same local network segment.
- 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:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H. Scored by CNA (cisco.com).
Official description
A vulnerability in the multicast DNS (mDNS) gateway feature of Cisco IOS XE Software for Wireless LAN Controllers (WLCs) could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition. This vulnerability is due to improper management of mDNS client entries. An attacker could exploit this vulnerability by connecting to the wireless network and sending a continuous stream of specific mDNS packets. A successful exploit could allow the attacker to cause the wireless controller to have high CPU utilization, which could lead to access points (APs) losing their connection to the controller and result in a DoS condition.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Incomplete Cleanup
The product does not properly clean up and remove temporary or supporting resources after they have been used.
How developers prevent this class of flaw
- Temporary files and other supporting resources should be deleted/released immediately after they are no longer needed.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
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 Incomplete Cleanup vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 8.8 High severity
- 7.5 High severity
- 7.8 High severity
- 9.8 Critical severity
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