#VU28522 Race condition in Mozilla NSS - CVE-2020-12399

Vulnerability identifier: #VU28522

Vulnerability risk: Medium

CVSSv4.0: 6.9 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/U:Green]

CVE-ID: CVE-2020-12399

CWE-ID: CWE-362

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Mozilla NSS
Universal components / Libraries / Libraries used by multiple products

Vendor: Mozilla

Description

The vulnerability allows a local user to gain access to sensitive information.

The vulnerability exists due to time differences in Mozilla NSS library during the process of generating a DSA signature, the nonce value 'k' is not padded, exposing the bit length. Combined with other techniques, this can result in the recovery of the DSA private key.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Mozilla NSS: 3.40 - 3.52.1

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External links
http://www.mozilla.org/en-US/security/advisories/mfsa2020-20/
http://bugzilla.mozilla.org/show_bug.cgi?id=1631576
http://bugzilla.redhat.com/show_bug.cgi?id=1826177

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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. However, proof of concept for this vulnerability is available.