6.8 Medium
CVSS2
Attack Vector
NETWORK
Attack Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:N/AC:M/Au:N/C:P/I:P/A:P
7.3 High
AI Score
Confidence
High
0.015 Low
EPSS
Percentile
86.9%
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.
lists.opensuse.org/opensuse-updates/2013-08/msg00035.html
secunia.com/advisories/54379
secunia.com/advisories/54533
svn.tartarus.org/sgt/putty/sshbn.c?sortby=date&r1=9977&r2=9976&pathrev=9977
www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/vuln-modmul.html
www.debian.org/security/2013/dsa-2736
www.openwall.com/lists/oss-security/2013/08/06/11