Cisco Webex Meetings Client Join Services acceptance of extraneous untrusted data with trusted data

Summaryinfo

A vulnerability marked as problematic has been reported in Cisco Webex Meetings. The affected element is an unknown function of the component Client Join Services. The manipulation leads to acceptance of extraneous untrusted data with trusted data. This vulnerability is uniquely identified as CVE-2025-20255. The attack is possible to be carried out remotely. No exploit exists. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Cisco Webex Meetings (the affected version is unknown). It has been rated as problematic. This issue affects an unknown code of the component Client Join Services. The manipulation with an unknown input leads to a acceptance of extraneous untrusted data with trusted data vulnerability. Using CWE to declare the problem leads to CWE-349. The product, when processing trusted data, accepts any untrusted data that is also included with the trusted data, treating the untrusted data as if it were trusted. Impacted is integrity. The summary by CVE is:

A vulnerability in client join services of Cisco Webex Meetings could allow an unauthenticated, remote attacker to manipulate cached HTTP responses within the meeting join service. This vulnerability is due to improper handling of malicious HTTP requests to the affected service. An attacker could exploit this vulnerability by manipulating stored HTTP responses within the service, also known as HTTP cache poisoning. A successful exploit could allow the attacker to cause the Webex Meetings service to return incorrect HTTP responses to clients.

It is possible to read the advisory at sec.cloudapps.cisco.com. The identification of this vulnerability is CVE-2025-20255 since 10/10/2024. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. It demands that the victim is doing some kind of user interaction. 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 07/15/2025).

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2025-16046). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

• Unified Communication Software

Vendor

• Cisco

Name

• Webex Meetings

License

• commercial

Website

• Vendor: https://www.cisco.com/

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Be aware that VulDB is the high quality source for vulnerability data.

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