CVE-2013-4207
Buffer overflow in sshbn.c in PuTTY before 0.63 allows remote SSH servers to cause a denial of service (crash) via an invalid DSA signature that is not properly handled during computation of a modular inverse and triggers the overflow during a division…
Does this matter?
Lower severity and a low EPSS score (1.83%). Track it; it rarely justifies an emergency change on its own.
Description
Buffer overflow in sshbn.c in PuTTY before 0.63 allows remote SSH servers to cause a denial of service (crash) via an invalid DSA signature that is not properly handled during computation of a modular inverse and triggers the overflow during a division by zero by the bignum functionality, a different vulnerability than CVE-2013-4206.
- CVSS 2.0
- 4.3 MEDIUMAV:N/AC:M/Au:N/C:N/I:N/A:P
- EPSS
- 1.83% probability · 79th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-119
- Affected
- putty/putty · simon tatham/putty
- Source
- secalert@redhat.com
EPSS 1.8% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- http://lists.opensuse.org/opensuse-updates/2013-08/msg00035.html
- http://secunia.com/advisories/54379Vendor Advisory
- http://secunia.com/advisories/54533
- http://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/vuln-bignum-division-by-zero.htmlVendor Advisory
- http://www.debian.org/security/2013/dsa-2736
- http://www.openwall.com/lists/oss-security/2013/08/06/11
- http://lists.opensuse.org/opensuse-updates/2013-08/msg00035.html
- http://secunia.com/advisories/54379Vendor Advisory
- http://secunia.com/advisories/54533
- http://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/vuln-bignum-division-by-zero.htmlVendor Advisory
- http://www.debian.org/security/2013/dsa-2736
- http://www.openwall.com/lists/oss-security/2013/08/06/11
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.