High
Security advisory
The auth_password function in auth-passwd.c in sshd in OpenSSH before 7.3 does not limit password lengths for password authentication, which allows remote attackers to cause a denial of service (crypt CPU consumption) via a long string.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2016-6515
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 12:11 UTC · Revision 1
Source evidence
The auth_password function in auth-passwd.c in sshd in OpenSSH before 7.3 does not limit password lengths for password authentication, which allows remote attackers to cause a denial of service (crypt CPU consumption) via a long string.
osv:CVE-2016-6515
Complete source record
{
"id": "f1c4f8eb4231df9a5eb4f52ee37e852d5a0a7bb59b55031a6133b21458e538d2",
"url": "https://osv.dev/vulnerability/CVE-2016-6515",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2016-6515",
"summary": "The auth_password function in auth-passwd.c in sshd in OpenSSH before 7.3 does not limit password lengths for password authentication, which allows remote attackers to cause a denial of service (crypt CPU consumption) via a long string.",
"evidence": "osv:CVE-2016-6515",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2016-6515",
"aliases": [
"CVE-2016-6515"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/openssh/openssh-portable",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"fixed": "99522ba7ec6963a05c04a156bf20e3ba3605987c"
},
{
"fixed": "fcd135c9df440bcd2d5870405ad3311743d78d97"
}
],
"database_specific": {
"extracted_events": [
{
"range": [
{
"introduced": "0"
},
{
"fixed": "7.3"
}
],
"source": "DESCRIPTION"
},
{
"range": [
{
"fixed": "fcd135c9df440bcd2d5870405ad3311743d78d97"
}
],
"source": "REFERENCES_COMMIT"
}
]
}
}
],
"versions": [
"V_7_2_P1",
"V_7_1_P1",
"V_7_0_P1",
"V_6_9_P1",
"V_6_8_P1",
"V_6_6_P1",
"V_6_5_P1",
"V_6_2_P1",
"V_6_1_P1",
"V_6_0_P1",
"V_5_7_P1",
"V_5_5_P1",
"V_5_2_P1",
"V_5_1_P1",
"V_5_0_P1",
"V_4_2_P1",
"V_3_9_P1",
"V_3_8_P1",
"AFTER_KRB5_GSSAPI_MERGE",
"BEFORE_KRB5_GSSAPI_MERGE",
"POST_KRB4_REMOVAL",
"PRE_KRB4_REMOVAL",
"AFTER_FREEBSD_PAM_MERGE",
"BEFORE_FREEBSD_PAM_MERGE",
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"V_3_2_2_P1",
"PRE_SW_KRBV",
"V_3_1_P1",
"V_3_0_1_P1",
"V_3_0_P1",
"V_2_5_2_P1",
"V_2_5_1_P2",
"V_2_5_1_P1",
"V_2_5_0_P1",
"PRE-REORDER",
"V_2_3_0_P1",
"PRE_CYGWIN_MERGE",
"V_2_2_0_P1",
"V_2_1_1_P4",
"V_2_1_1_P3",
"ABOUT_TO_ADD_INET_ATON",
"V_2_1_1_P2",
"V_2_1_1_P1",
"PRE_NEW_LOGIN_CODE",
"V_2_1_0_P3",
"V_2_1_0_P2",
"V_2_1_0_P1",
"V_2_1_0",
"V_2_0_0_BETA2",
"V_2_0_0_BETA1",
"V_2_0_0_TEST1",
"V_1_2_3_TEST3",
"V_1_2_3_TEST2",
"V_1_2_3_TEST1",
"V_1_2_3",
"V_1_2_3_PRE5",
"V_1_2_3_PRE4",
"V_1_2_3_PRE3",
"V_1_2_3_PRE2",
"V_1_2_3_PRE1",
"V_1_2_2_P1",
"V_1_2_2",
"V_1_2_2_PRE29",
"V_1_2_2_PRE28",
"V_1_2_1_PRE27",
"V_1_2_1_PRE26",
"PRE_IPV6",
"V_1_2_1_PRE25",
"V_1_2_1_PRE24",
"V_1_2_1_PRE23",
"V_1_2_1_PRE22",
"PRE_FIXPATHS_INTEGRATION",
"V_1_2_1_PRE21",
"V_1_2_1_PRE20",
"V_1_2_1_PRE19",
"PRE_HPUX_INTEGRATION",
"V_1_2_1_PRE18",
"V_1_2PRE17",
"V_1_2_PRE16",
"V_1_2_PRE15",
"V_1_2_PRE14",
"V_1_2_PRE13",
"V_1_2_PRE12",
"V_1_2_PRE11",
"V_1_2_PRE10",
"V_1_2_PRE9",
"V_1_2_PRE8",
"V_1_2_PRE7",
"V_1_2_PRE6",
"V_1_2_PRE5",
"V_1_2_PRE4",
"PRE_DAN_PATCH_MERGE"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2016-6515.json",
"vanir_signatures": [
{
"id": "CVE-2016-6515-a7ac801a",
"digest": {
"length": 1046,
"function_hash": "226840948738846026054403909505423905859"
},
"source": "https://github.com/openssh/openssh-portable/commit/fcd135c9df440bcd2d5870405ad3311743d78d97",
"target": {
"file": "auth-passwd.c",
"function": "auth_password"
},
"deprecated": false,
"signature_type": "Function",
"signature_version": "v1"
},
{
"id": "CVE-2016-6515-f74bc6a0",
"digest": {
"threshold": 0.9,
"line_hashes": [
"169366794320422204000709960000445355030",
"311121508538256338473633648009588614623",
"210215936786631902887231947746032519312",
"145147796172036403093771438374944323202",
"34022028665672401654215887975195649129",
"13648517431284205482544467659725921705",
"194613709597506156553679113958316693368"
]
},
"source": "https://github.com/openssh/openssh-portable/commit/fcd135c9df440bcd2d5870405ad3311743d78d97",
"target": {
"file": "auth-passwd.c"
},
"deprecated": false,
"signature_type": "Line",
"signature_version": "v1"
}
],
"vanir_signatures_modified": "2026-10-20T13:18:00Z"
}
}
],
"modified": "2026-10-20T13:18:00.055802108Z",
"provider": "osv",
"references": [
"https://cert-portal.siemens.com/productcert/pdf/ssa-412672.pdf",
"https://cert-portal.siemens.com/productcert/pdf/ssa-676336.pdf",
"https://lists.debian.org/debian-lts-announce/2018/09/msg00010.html",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/X2L6RW34VFNXYNVVN2CN73YAGJ5VMTFU/",
"https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbhf03779en_us",
"https://www.exploit-db.com/exploits/40888/",
"https://access.redhat.com/errata/RHSA-2017:2029",
"https://security.FreeBSD.org/advisories/FreeBSD-SA-17:06.openssh.asc",
"https://security.netapp.com/advisory/ntap-20171130-0003/",
"https://github.com/openssh/openssh-portable/commit/fcd135c9df440bcd2d5870405ad3311743d78d97"
],
"provider_metadata": {
"unresolved_ranges": [
{
"cpes": [
"cpe:2.3:a:openbsd:openssh:*:p2:*:*:*:*:*:*"
],
"vendor_product": "openbsd:openssh",
"extracted_events": [
{
"range": [
{
"last_affected": "7.2"
}
],
"source": "CPE_RANGE"
}
]
},
{
"cpes": [
"cpe:2.3:o:fedoraproject:fedora:24:*:*:*:*:*:*:*"
],
"vendor_product": "fedoraproject:fedora",
"extracted_events": [
{
"range": [
{
"introduced": "24"
},
{
"last_affected": "24"
}
],
"source": "CPE_STRING"
}
]
}
]
}
},
"related_cves": [
{
"value": "CVE-2016-6515",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 387479,
"published_at": "2016-08-07T21:59:09.943+00:00"
}