{"id":"CVE-2016-20012","details":"OpenSSH through 8.7 allows remote attackers, who have a suspicion that a certain combination of username and public key is known to an SSH server, to test whether this suspicion is correct. This occurs because a challenge is sent only when that combination could be valid for a login session. NOTE: the vendor does not recognize user enumeration as a vulnerability for this product","modified":"2026-04-10T03:48:43.183561Z","published":"2021-09-15T20:15:07.310Z","references":[{"type":"ADVISORY","url":"https://utcc.utoronto.ca/~cks/space/blog/tech/SSHKeysAreInfoLeak"},{"type":"ADVISORY","url":"https://www.openwall.com/lists/oss-security/2018/08/24/1"},{"type":"ADVISORY","url":"https://security.netapp.com/advisory/ntap-20211014-0005/"},{"type":"REPORT","url":"https://github.com/openssh/openssh-portable/pull/270#issuecomment-920577097"},{"type":"REPORT","url":"https://github.com/openssh/openssh-portable/pull/270#issuecomment-943909185"},{"type":"FIX","url":"https://github.com/openssh/openssh-portable/pull/270"},{"type":"EVIDENCE","url":"https://rushter.com/blog/public-ssh-keys/"},{"type":"EVIDENCE","url":"https://github.com/openssh/openssh-portable/blob/d0fffc88c8fe90c1815c6f4097bc8cbcabc0f3dd/auth2-pubkey.c#L261-L265"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/openssh/openssh-portable","events":[{"introduced":"0"},{"last_affected":"e1a596186c81e65a34ce13076449712d3bf97eb4"}],"database_specific":{"versions":[{"introduced":"0"},{"last_affected":"8.7"}]}}],"versions":["ABOUT_TO_ADD_INET_ATON","AFTER_FREEBSD_PAM_MERGE","AFTER_KRB5_GSSAPI_MERGE","BEFORE_FREEBSD_PAM_MERGE","BEFORE_KRB5_GSSAPI_MERGE","POST_KRB4_REMOVAL","PRE-REORDER","PRE_CYGWIN_MERGE","PRE_DAN_PATCH_MERGE","PRE_FIXPATHS_INTEGRATION","PRE_HPUX_INTEGRATION","PRE_IPV6","PRE_KRB4_REMOVAL","PRE_NEW_LOGIN_CODE","PRE_SW_KRBV","V_1_2PRE17","V_1_2_1_PRE18","V_1_2_1_PRE19","V_1_2_1_PRE20","V_1_2_1_PRE21","V_1_2_1_PRE22","V_1_2_1_PRE23","V_1_2_1_PRE24","V_1_2_1_PRE25","V_1_2_1_PRE26","V_1_2_1_PRE27","V_1_2_2","V_1_2_2_P1","V_1_2_2_PRE28","V_1_2_2_PRE29","V_1_2_3","V_1_2_3_PRE1","V_1_2_3_PRE2","V_1_2_3_PRE3","V_1_2_3_PRE4","V_1_2_3_PRE5","V_1_2_3_TEST1","V_1_2_3_TEST2","V_1_2_3_TEST3","V_1_2_PRE10","V_1_2_PRE11","V_1_2_PRE12","V_1_2_PRE13","V_1_2_PRE14","V_1_2_PRE15","V_1_2_PRE16","V_1_2_PRE4","V_1_2_PRE5","V_1_2_PRE6","V_1_2_PRE7","V_1_2_PRE8","V_1_2_PRE9","V_2_0_0_BETA1","V_2_0_0_BETA2","V_2_0_0_TEST1","V_2_1_0","V_2_1_0_P1","V_2_1_0_P2","V_2_1_0_P3","V_2_1_1_P1","V_2_1_1_P2","V_2_1_1_P3","V_2_1_1_P4","V_2_2_0_P1","V_2_3_0_P1","V_2_5_0_P1","V_2_5_1_P1","V_2_5_1_P2","V_2_5_2_P1","V_3_0_1_P1","V_3_0_P1","V_3_1_P1","V_3_2_2_P1","V_3_4_P1","V_3_6_1_P1","V_3_8_P1","V_3_9_P1","V_4_2_P1","V_5_0_P1","V_5_1_P1","V_5_2_P1","V_5_5_P1","V_5_7_P1","V_6_0_P1","V_6_1_P1","V_6_2_P1","V_6_5_P1","V_6_6_P1","V_6_8_P1","V_6_9_P1","V_7_0_P1","V_7_1_P1","V_7_2_P1","V_7_3_P1","V_7_4_P1","V_7_5_P1","V_7_6_P1","V_7_7_P1","V_7_8_P1","V_7_9_P1","V_8_0_P1","V_8_1_P1","V_8_2_P1","V_8_4_P1","V_8_5_P1","V_8_6_P1","V_8_7_P1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2016-20012.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N"}]}