#VU42653 Heap-based buffer overflow in Simon Tatham products - CVE-2013-4852

Vulnerability identifier: #VU42653

Vulnerability risk: Medium

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2013-4852

CWE-ID: CWE-122

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
WinSCP
Client/Desktop applications / File managers, FTP clients
Debian Linux
Operating systems & Components / Operating system
Opensuse
Operating systems & Components / Operating system
PuTTY
Client/Desktop applications / Software for system administration

Vendor: winscp.sourceforge.net
Debian
SUSE
Simon Tatham

Description

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

The vulnerability exists due to a boundary error in Integer overflow in PuTTY 0.62 and earlier, WinSCP before 5.1.6, and other products that use PuTTY. A remote attacker can use a negative size value in an RSA key signature during the SSH handshake to trigger heap-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
Cybersecurity Help is currently unaware of any official solution to address this vulnerability.

Vulnerable software versions

WinSCP: 3.7.6 - 5.1.4

Debian Linux: 3.7.6 - 7.1

Opensuse: 3.7.6 - 12.3

PuTTY: 0.45 - 0.61

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External links
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=718779
https://lists.opensuse.org/opensuse-updates/2013-08/msg00035.html
https://lists.opensuse.org/opensuse-updates/2013-08/msg00041.html
https://secunia.com/advisories/54379
https://secunia.com/advisories/54517
https://secunia.com/advisories/54533
https://svn.tartarus.org/sgt?view=revision&sortby=date&revision=9896
https://winscp.net/tracker/show_bug.cgi?id=1017
https://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/vuln-signature-stringlen.html
https://www.debian.org/security/2013/dsa-2736
https://www.search-lab.hu/advisories/secadv-20130722

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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.