Mozilla Firefox up to 68.x Content Security Policy Empty String Javascript default permission

Summaryinfo

A vulnerability, which was classified as critical, was found in Mozilla Firefox up to 68.x. Affected by this issue is some unknown functionality of the component Content Security Policy. Executing a manipulation as part of Empty String can lead to default permission (Javascript). This vulnerability is handled as CVE-2019-11738. The attack can be executed remotely. There is not any exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Mozilla Firefox up to 68.x (Web Browser). It has been declared as critical. This vulnerability affects some unknown functionality of the component Content Security Policy. The manipulation as part of a Empty String leads to a default permission vulnerability (Javascript). The CWE definition for the vulnerability is CWE-276. During installation, installed file permissions are set to allow anyone to modify those files. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

If a Content Security Policy (CSP) directive is defined that uses a hash-based source that takes the empty string as input, execution of any javascript: URIs will be allowed. This could allow for malicious JavaScript content to be run, bypassing CSP permissions. This vulnerability affects Firefox < 69 and Firefox ESR < 68.1.

The weakness was released 09/27/2019 as MFSA 2019-25 as confirmed security advisory (Website). The advisory is shared for download at mozilla.org. This vulnerability was named CVE-2019-11738 since 05/03/2019. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 09/11/2020). The MITRE ATT&CK project declares the attack technique as T1222.

Upgrading to version 69.0 eliminates this vulnerability. A possible mitigation has been published immediately after the disclosure of the vulnerability.

Entries connected to this vulnerability are available at VDB-142392, VDB-142393, VDB-142394 and VDB-142395. Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Web Browser

Vendor

• Mozilla

Name

• Firefox

Version

• 68.x

License

• open-source

Website

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

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Once again VulDB remains the best source for vulnerability data.

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