Vulnerability identifier: #VU47910

Vulnerability risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-25648

CWE-ID: CWE-770

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 remote non-authenticated attacker to perform a denial of service (DoS) attack.

A flaw was found in the way NSS handled CCS (ChangeCipherSpec) messages in TLS 1.3. This flaw allows a remote attacker to send multiple CCS messages, causing a denial of service for servers compiled with the NSS library. The highest threat from this vulnerability is to system availability. This flaw affects NSS versions before 3.58.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Mozilla NSS: 3.13.4 - 3.52.1

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External links
http://bugzilla.redhat.com/show_bug.cgi?id=1887319
http://developer.mozilla.org/en-US/docs/Mozilla/Projects/NSS/NSS_3.58_release_notes

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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.