#VU21371 Spoofing attack in Mozilla Thunderbird - CVE-2019-11755

Vulnerability identifier: #VU21371

Vulnerability risk: Low

CVSSv4.0: 1 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2019-11755

CWE-ID: CWE-451

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Mozilla Thunderbird
Client/Desktop applications / Messaging software

Vendor: Mozilla

Description

The vulnerability allows a remote attacker to perform spoofing attack.

The vulnerability exists due to incorrect processing of S/MIME messages, consisting of an inner encryption layer and an outer SignedData layeruser-supplied data. A remote attacker can create a specially crafted message and make it look as it was signed with a valid signature. Although the signer might have had no access to the contents of the encrypted message, and might have stripped a different signature from the encrypted message.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Mozilla Thunderbird: 60.0 - 68.1.0

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External links
https://www.mozilla.org/en-US/security/advisories/mfsa2019-32/

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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.