A vulnerability was found in Mozilla Firefox up to 73.x (Web Browser). It has been rated as critical. This issue affects an unknown part of the component CSS Block Handler. The manipulation with an unknown input leads to a injection vulnerability. Using CWE to declare the problem leads to 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. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

When protecting CSS blocks with the nonce feature of Content Security Policy, the @import statement in the CSS block could allow an attacker to inject arbitrary styles, bypassing the intent of the Content Security Policy. This vulnerability affects Firefox < 74.

The weakness was released 03/25/2020. The identification of this vulnerability is CVE-2020-6813 since 01/10/2020. 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 03/26/2020). The attack technique deployed by this issue is T1055 according to MITRE ATT&CK.

Upgrading to version 74.0 eliminates this vulnerability.

Entries connected to this vulnerability are available at 152353, 152348 and 152347.

Productinfo

Type

• Web Browser

Vendor

• Mozilla

Name

• Firefox

Version

• 73.x

License

• open-source

CPE 2.3info

• 🔍

CPE 2.2info

• 🔍

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