#VU40296 Input validation error in Fedora and Botan - CVE-2016-2850

Vulnerability identifier: #VU40296

Vulnerability risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2016-2850

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Fedora
Operating systems & Components / Operating system
Botan
Universal components / Libraries / Libraries used by multiple products

Vendor: Fedoraproject
Randombit

Description

The vulnerability allows a remote non-authenticated attacker to manipulate data.

Botan 1.11.x before 1.11.29 does not enforce TLS policy for (1) signature algorithms and (2) ECC curves, which allows remote attackers to conduct downgrade attacks via unspecified vectors.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Fedora: 24

Botan: 1.11.0 - 1.11.28, 24

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External links
https://botan.randombit.net/security.html
https://lists.fedoraproject.org/pipermail/package-announce/2016-May/183669.html
https://marc.info/?l=botan-devel&m=145852488622892&w=2
https://security.gentoo.org/glsa/201701-23

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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.