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CVE-2023-20109

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

6.6 MEDIUMActively exploited (CISA KEV)EPSS 2.48%
  1. Published27 Sept 2023
  2. Added to CISA KEV10 Oct 2023
  3. Remediation due31 Oct 2023
Actively exploited (CISA KEV)

Cisco IOS and IOS XE contain an out-of-bounds write vulnerability in the Group Encrypted Transport VPN (GET VPN) feature that could allow an authenticated, remote attacker who has administrative control of either a group member or a key server to execute malicious code or cause a device to crash.

Added to KEV: 10 Oct 2023Federal remediation due: 31 Oct 2023

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 breakdown

Attack vectorNetwork
Attack complexityHigh
Privileges requiredHigh
User interactionNone
ScopeUnchanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H

Affected products

Cisco iOS12.4\(22\)md · 12.4\(22\)md1 · 12.4\(22\)md2 · 12.4\(22\)mda

Remediation

No fixed version is recorded in the NVD data. Check the vendor advisory for the latest guidance.

References

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Frequently asked

Is CVE-2023-20109 being actively exploited?

Yes. CVE-2023-20109 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added 10 Oct 2023.

How severe is CVE-2023-20109?

CVE-2023-20109 has a CVSS 3.1 base score of 6.6, rated medium. EPSS estimates a 2.48% probability of exploitation.

Which products are affected by CVE-2023-20109?

Affected products include Cisco iOS.

How do I fix CVE-2023-20109?

Apply the vendor's patch or advisory guidance, then verify no affected versions remain across your devices.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2023-20109 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. Because it is on the CISA KEV list, Secuno flags any affected asset as top-priority automatically. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.