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CVE-2023-20109KEV

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

Severity
Medium6.6CVSS 3.1, Medium
EPSS
2%
Published
27 Sept 2023
Updated
17 Jun 2026

Description

Title, description and vendor guidance are quoted from the source records.

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.

Weakness: CWE-787

Known exploited

Added to CISA KEV on 10 Oct 2023

Federal remediation due date: 31 Oct 2023

Required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Exploit prediction

2% probability of exploitation in the next 30 days (percentile 83%).

CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H

Affected products

Patcharo shows this vulnerability for information but does not match versions for this product yet.

  • Cisco IOS · 12.4(24)T, 12.4(24)T3, 12.4(22)T1, 12.4(24)T5, 12.4(24)T4, 12.4(22)T, 12.4(24)T8, 12.4(24)T2, 12.4(22)T5, 12.4(22)T4, 12.4(24)T1, 12.4(24)T7 and 662 more
  • Cisco Cisco IOS XE Software · 3.7.0S, 3.7.1S, 3.7.2S, 3.7.3S, 3.7.4S, 3.7.5S, 3.7.6S, 3.7.7S, 3.7.4aS, 3.7.2tS, 3.7.0bS, 3.7.1aS and 352 more

References

Provenance

Every fact on this page comes from the sources below. Nothing is written by an AI.

Cisco (CVE record)
Cisco (CVE record) · 27 Sept 2026, 23:46 UTC · Parser patcharo-cve5/1.1.0
CISA Known Exploited Vulnerabilities
CISA Known Exploited Vulnerabilities · 27 Sept 2026, 23:42 UTC · Parser patcharo-kev/1.0.0
NVD
NVD · 27 Sept 2026, 23:44 UTC · Parser patcharo-nvd/1.0.0
FIRST EPSS
FIRST EPSS · 27 Sept 2026, 23:46 UTC · Parser patcharo-epss/1.0.0

Last verified: 28 Sept 2026, 02:31 UTC