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UK Cyber Defence
VulnerabilityAnalyzed

CVE-2023-20109

Cisco IOS and IOS XE Group Encrypted Transport VPN Out-of-Bounds Write Vulnerability

KEVMEDIUM 6.6EPSS 2.34%

Does this matter?

Known to be exploited in the wild (CISA KEV, CISA remediation deadline 31 October 2023). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.

Description

A vulnerability in the Cisco Group Encrypted Transport VPN (GET VPN) feature of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, remote attacker who has administrative control of either a group member or a key server to execute arbitrary code on an affected device or cause the device to crash. This vulnerability is due to insufficient validation of attributes in the Group Domain of Interpretation (GDOI) and G-IKEv2 protocols of the GET VPN feature. An attacker could exploit this vulnerability by either compromising an installed key server or modifying the configuration of a group member to point to a key server that is controlled by the attacker. A successful exploit could allow the attacker to execute arbitrary code and gain full control of the affected system or cause the affected system to reload, resulting in a denial of service (DoS) condition. For more information, see the Details ["#details"] section of this advisory.

CVSS 3.1
6.6 MEDIUMCVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
EPSS
2.34% probability · 83th percentile
CISA KEV
Listed 10 October 2023 · due 31 October 2023
Weakness
CWE-787
Affected
cisco/ios · cisco/ios xe
Source
psirt@cisco.com

CISA notes

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-getvpn-rce-g8qR68sx; https://nvd.nist.gov/vuln/detail/CVE-2023-20109

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.