Input validation error in PuTTY

1) Input validation error

EUVDB-ID: #VU33817

Risk: Medium

CVSSv3.1: 4.6 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2015-5309

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

The vulnerability allows a remote non-authenticated attacker to perform service disruption.

Integer overflow in the terminal emulator in PuTTY before 0.66 allows remote attackers to cause a denial of service (memory corruption) or possibly execute arbitrary code via an ECH (erase characters) escape sequence with a large parameter value, which triggers a buffer underflow.

Mitigation

Install update from vendor's website.

Vulnerable software versions

PuTTY: 0.45 - 0.65

External links

http://lists.fedoraproject.org/pipermail/package-announce/2015-December/173021.html
http://lists.fedoraproject.org/pipermail/package-announce/2015-December/173094.html
http://lists.opensuse.org/opensuse-updates/2015-11/msg00099.html
http://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/vuln-ech-overflow.html
http://www.debian.org/security/2015/dsa-3409
http://www.securitytracker.com/id/1034308
http://security.gentoo.org/glsa/201606-01

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.