Buffer overflow in Putty
CVE-2013-4206
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v2 metric
CVSS v2 base score 6.8 (Medium). Vector: AV:N/AC:M/Au:N/C:P/I:P/A:P. This CVE predates CVSS v3 and has no v3 score from NVD.
EPSS exploit prediction
EPSS: 0.025 (84.5th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 85th percentile — 84.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.025 · newest: 0.025 · change: 0.000
Affected products
- Putty — versions 0.45, 0.46, 0.47
- Simon Tatham Putty — versions 0.53
Weakness classification (CWE)
References
- www.openwall.com/lists/oss-security/2013/08/06/11 (mailing-list)
- secunia.com/advisories/54533 (third-party-advisory)
- www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/vuln-modmul.html (Vendor Advisory)
- www.debian.org/security/2013/dsa-2736 (vendor-advisory)
- lists.opensuse.org/opensuse-updates/2013-08/msg00035.html (vendor-advisory)
- secunia.com/advisories/54379 (Vendor Advisory, third-party-advisory)
- svn.tartarus.org/sgt/putty/sshbn.c (Patch)