Vulnerability identifier: #VU53727

Vulnerability risk: Low

CVSSv3.1: 3.8 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-29958

CWE-ID: CWE-200

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Firefox for iOS
Mobile applications / Apps for mobile phones

Vendor: Mozilla

Description

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to excessive data output by the application during private browsing. When a download was initiated, the client did not check whether it was in normal or private browsing mode, which led to private mode cookies being shared in normal browsing mode.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Firefox for iOS: 8.0 - 33.0

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External links
http://www.mozilla.org/en-US/security/advisories/mfsa2021-25/

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.