CVE-2013-4206

critical

Description

Heap-based buffer underflow in the modmul function in sshbn.c in PuTTY before 0.63 allows remote SSH servers to cause a denial of service (crash) and possibly trigger memory corruption or code execution via a crafted DSA signature, which is not properly handled when performing certain bit-shifting operations during modular multiplication.

References

http://www.openwall.com/lists/oss-security/2013/08/06/11

http://www.debian.org/security/2013/dsa-2736

http://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/vuln-modmul.html

http://svn.tartarus.org/sgt/putty/sshbn.c?sortby=date&r1=9977&r2=9976&pathrev=9977

http://secunia.com/advisories/54533

http://secunia.com/advisories/54379

http://lists.opensuse.org/opensuse-updates/2013-08/msg00035.html

Details

Source: Mitre, NVD

Published: 2013-08-19

Updated: 2021-08-06

Risk Information

CVSS v2

Base Score: 6.8

Vector: CVSS2#AV:N/AC:M/Au:N/C:P/I:P/A:P

Severity: Medium

CVSS v3

Base Score: 9.8

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity: Critical