Mozilla Firefox ESR up to 115.22/128.9 on Windows Copy as cURL escape output

Summaryinfo

A vulnerability identified as problematic has been detected in Mozilla Firefox ESR up to 115.22/128.9 on Windows. This affects an unknown part of the component Copy as cURL Handler. The manipulation leads to Remote Code Execution. This vulnerability is traded as CVE-2025-4084. It is possible to initiate the attack remotely. There is no exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Mozilla Firefox ESR up to 115.22/128.9 on Windows. It has been rated as problematic. This issue affects some unknown functionality of the component Copy as cURL Handler. The manipulation with an unknown input leads to a remote code execution vulnerability. Using CWE to declare the problem leads to CWE-116. The product prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. As a result, the intended structure of the message is not preserved. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

Due to insufficient escaping of the special characters in the "copy as cURL" feature, an attacker could trick a user into using this command, potentially leading to local code execution on the user's system. *This bug only affects Firefox for Windows. Other versions of Firefox are unaffected.* This vulnerability affects Firefox ESR < 128.10, Firefox ESR < 115.23, and Thunderbird ESR < 128.10.

It is possible to read the advisory at bugzilla.mozilla.org. The identification of this vulnerability is CVE-2025-4084 since 04/29/2025. The exploitation is known to be difficult. 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 $5k-$25k at the moment (estimation calculated on 08/16/2025).

The vulnerability scanner Nessus provides a plugin with the ID 234931 (Mozilla Firefox ESR < 115.23), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 115.23 or 128.10 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (234931) and CERT Bund (WID-SEC-2025-1850). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

• Xerox FreeFlow Print Server

Productinfo

Type

• Web Browser

Vendor

• Mozilla

Name

• Firefox ESR

Version

• 115.0
• 115.1
• 115.2
• 115.3
• 115.4
• 115.5
• 115.6
• 115.7
• 115.8
• 115.9
• 115.10
• 115.11
• 115.12
• 115.13
• 115.14
• 115.15
• 115.16
• 115.17
• 115.18
• 115.19
• 115.20
• 115.21
• 115.22
• 128.0
• 128.1
• 128.2
• 128.3
• 128.4
• 128.5
• 128.6
• 128.7
• 128.8
• 128.9

License

• open-source

Website

• Vendor: https://www.mozilla.org/

CPE 2.3info

• 🔍
• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍
• 🔍

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Discussion