Cisco Secure Firewall Threat Defense Software DCE/RPC information disclosure

Summaryinfo

A vulnerability, which was classified as problematic, has been found in Cisco Secure Firewall Threat Defense Software and UTD SNORT IPS Engine Software. The impacted element is an unknown function of the component DCE/RPC. This manipulation causes information disclosure. This vulnerability is tracked as CVE-2026-20027. The attack is possible to be carried out remotely. No exploit exists. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability has been found in Cisco Secure Firewall Threat Defense Software and UTD SNORT IPS Engine Software (affected version unknown) and classified as problematic. Affected by this vulnerability is an unknown functionality of the component DCE/RPC. The manipulation with an unknown input leads to a information disclosure vulnerability. The CWE definition for the vulnerability is CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. As an impact it is known to affect confidentiality. The summary by CVE is:

Multiple Cisco products are affected by a vulnerability in the processing of DCE/RPC requests that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to leak sensitive information or to restart, resulting in an interruption of packet inspection. This vulnerability is due to an error in buffer handling logic when processing DCE/RPC requests, which can result in a buffer out-of-bounds read. An attacker could exploit this vulnerability by sending a large number of DCE/RPC requests through an established connection that is inspected by Snort 3. A successful exploit could allow the attacker to obtain sensitive information in the Snort 3 data stream.

It is possible to read the advisory at sec.cloudapps.cisco.com. This vulnerability is known as CVE-2026-20027 since 10/08/2025. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 01/08/2026). The attack technique deployed by this issue is T1592 according to MITRE ATT&CK.

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-0041). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

• Open Source Snort
• Cisco Secure Firewall Threat Defense
• Cisco IOS XE
• Cisco Meraki MX

Productinfo

Type

• Firewall Software

Vendor

• Cisco

Name

• Secure Firewall Threat Defense Software
• UTD SNORT IPS Engine Software

License

• commercial

Website

• Vendor: https://www.cisco.com/

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