Stack-based buffer overflow in PuTTY

1) Stack-based buffer overflow

EUVDB-ID: #VU32320

Risk: High

CVSSv3.1: 8.8 [AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2016-2563

CWE-ID: CWE-121 - Stack-based buffer overflow

Exploit availability: Yes

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error when processing a crafted SCP-SINK file-size response to an SCP download request. A remote unauthenticated attacker can trigger stack-based buffer overflow and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation

Update to version 0.67.

Vulnerable software versions

PuTTY: 0.45 - 0.66

External links

http://lists.opensuse.org/opensuse-updates/2016-05/msg00131.html
http://seclists.org/fulldisclosure/2016/Mar/22
http://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/vuln-pscp-sink-sscanf.html
http://www.securityfocus.com/bid/84296
http://www.securitytracker.com/id/1035257
http://github.com/tintinweb/pub/tree/master/pocs/cve-2016-2563
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. However, proof of concept for this vulnerability is available.