ZDF
Sign inSign up

Vulnerabilities

Vulnerability · CVE-2023-20109

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

Published Sep 27, 2023 · catalog updated Jun 16, 2026 · Cisco IOS and IOS XE

Patch now

CVE-2023-20109 is in the CISA known-exploited catalog, due Oct 31, 2023. Confirm Cisco IOS and IOS XE against the vendor advisory and apply that fix. The CVSS score does not change the priority.

Severity
Medium6.6
Known exploitation
CISA KEV and VulnCheck KEV
EPSS
2.48%
Remediation
Remediation guidance
Affected products
cpe cisco/ios · cpe cisco/ios xe · vendor Cisco IOS and IOS XE

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe cisco/ios12.4\(22\)md
  • cpe cisco/ios12.4\(22\)md1
  • cpe cisco/ios12.4\(22\)md2
  • cpe cisco/ios12.4\(22\)mda
  • cpe cisco/ios12.4\(22\)mda1
  • cpe cisco/ios12.4\(22\)mda2
  • cpe cisco/ios12.4\(22\)mda3
  • cpe cisco/ios12.4\(22\)mda4
  • cpe cisco/ios xe3.3.0sg
  • vendor Cisco IOS and IOS XEversion unspecified

How to fix CVE-2023-20109

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

CVE-2023-20109 is in the CISA known-exploited catalog, due Oct 31, 2023. Confirm Cisco IOS and IOS XE against the vendor advisory and apply that fix. The CVSS score does not change the priority.

Which versions are affected?

Compare what you have installed with cisco/ios xe 3.3.0sg. Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

What should an analyst verify?

CWE-787: Out-of-bounds Write. EPSS 2.48%. The CISA KEV listing is the exploitation evidence. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Technology hubs

Cisco security

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Sep 27, 2023 · Catalog

    Detected

    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

  2. Oct 10, 2023 · CISA KEV

    Known exploited

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

  3. Oct 31, 2023 · CISA KEV

    Remediation due

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

  4. Jun 16, 2026 · Catalog

    Updated

    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

Sources

  • CISA KEVConfirmed exploitationCVE-2023-20109

    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.

    cisa.gov
  • CVE.orgVulnerability recordCVE-2023-20109

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2023-20109

    30-day exploitation probability 2.5%

    first.org
  • NIST NVDVulnerability recordCVE-2023-20109

    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 affec

    nvd.nist.gov
  • VulnCheck KEVConfirmed exploitationCVE-2023-20109

    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

    vulncheck.com

References

Freshness

Last verified in this catalog Oct 17, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.