{"id":"CVE-2013-4207","url":"https://www.cyber-defence.io/tools/cve/CVE-2013-4207","generatedAt":"2026-10-27T19:53:09.239Z","title":"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…","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.","published":"2013-08-19T23:55:09.000Z","lastModified":"2026-06-16T23:56:49.000Z","status":"Modified","sourceIdentifier":"secalert@redhat.com","cvss":{"version":"2.0","score":4.3,"severity":"MEDIUM","vector":"AV:N/AC:M/Au:N/C:N/I:N/A:P"},"cwe":["CWE-119"],"affected":["putty/putty","simon tatham/putty"],"epss":{"score":0.01827,"percentile":0.78682,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (1.83%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"http://lists.opensuse.org/opensuse-updates/2013-08/msg00035.html","source":"secalert@redhat.com"},{"url":"http://secunia.com/advisories/54379","tags":["Vendor Advisory"],"source":"secalert@redhat.com"},{"url":"http://secunia.com/advisories/54533","source":"secalert@redhat.com"},{"url":"http://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/vuln-bignum-division-by-zero.html","tags":["Vendor Advisory"],"source":"secalert@redhat.com"},{"url":"http://www.debian.org/security/2013/dsa-2736","source":"secalert@redhat.com"},{"url":"http://www.openwall.com/lists/oss-security/2013/08/06/11","source":"secalert@redhat.com"},{"url":"http://lists.opensuse.org/opensuse-updates/2013-08/msg00035.html","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://secunia.com/advisories/54379","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://secunia.com/advisories/54533","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/vuln-bignum-division-by-zero.html","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.debian.org/security/2013/dsa-2736","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.openwall.com/lists/oss-security/2013/08/06/11","source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2013-4207","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}