Mozilla Firefox up to 76.x Address Bar injection

Summaryinfo

A vulnerability marked as critical has been reported in Mozilla Firefox up to 76.x. The impacted element is an unknown function of the component Address Bar. Performing a manipulation results in injection. This vulnerability is identified as CVE-2020-12408. The attack can be initiated remotely. There is not any exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, was found in Mozilla Firefox up to 76.x (Web Browser). This affects an unknown code of the component Address Bar. The manipulation with an unknown input leads to a injection vulnerability. CWE is classifying the issue as CWE-74. The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

When browsing a document hosted on an IP address, an attacker could insert certain characters to flip domain and path information in the address bar. This vulnerability affects Firefox < 77.

The weakness was released 07/09/2020 as Bug 1623888 as not defined bug report (Bugzilla). It is possible to read the advisory at bugzilla.mozilla.org. This vulnerability is uniquely identified as CVE-2020-12408 since 04/28/2020. It is possible to initiate the attack remotely. No form of authentication is needed for 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 08/09/2025). The attack technique deployed by this issue is T1055 according to MITRE ATT&CK.

The vulnerability scanner Nessus provides a plugin with the ID 246695 (Linux Distros Unpatched Vulnerability : CVE-2020-12408), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 77.0 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (246695). Entries connected to this vulnerability are available at VDB-157795, VDB-157794, VDB-157792 and VDB-157790. Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

• Web Browser

Vendor

• Mozilla

Name

• Firefox

Version

• 76.x

License

• open-source

Website

• Vendor: https://www.mozilla.org/
• Product: https://www.mozilla.org/en-US/firefox/

CPE 2.3info

• 🔍

CPE 2.2info

• 🔍

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

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

Discussion