Critical
Security advisory
An issue was discovered in Squid before 5.0.2. A remote attacker can replay a sniffed Digest Authentication nonce to gain access to resources that are otherwise forbidden. This occurs because the attacker can overflow the nonce reference counter (a short integer). Remote code execution may occur if the pooled token credentials are freed (instead of replayed as valid credentials).
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2020-11945
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 09:26 UTC · Revision 1
Source evidence
An issue was discovered in Squid before 5.0.2. A remote attacker can replay a sniffed Digest Authentication nonce to gain access to resources that are otherwise forbidden. This occurs because the attacker can overflow the nonce reference counter (a short integer). Remote code execution may occur if the pooled token credentials are freed (instead of replayed as valid credentials).
osv:CVE-2020-11945
Complete source record
{
"id": "8487d70cbb4a70146bb1b25191e6616908914cb429f3490179a5809be91bedc3",
"url": "https://osv.dev/vulnerability/CVE-2020-11945",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2020-11945",
"summary": "An issue was discovered in Squid before 5.0.2. A remote attacker can replay a sniffed Digest Authentication nonce to gain access to resources that are otherwise forbidden. This occurs because the attacker can overflow the nonce reference counter (a short integer). Remote code execution may occur if the pooled token credentials are freed (instead of replayed as valid credentials).",
"evidence": "osv:CVE-2020-11945",
"products": [],
"severity": "critical",
"structured": {
"id": "CVE-2020-11945",
"aliases": [
"CVE-2020-11945"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/squid-cache/squid",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"last_affected": "6cfeb300caf423ff49a0511d8bd43a56f3418273"
},
{
"fixed": "1683cc19eea84e522beb463d00358a4265989f90"
},
{
"fixed": "3953412ebd17d99eb6bab35695880d4b09c4ac2d"
},
{
"fixed": "eeebf0f37a72a2de08348e85ae34b02c34e9a811"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:squid-cache:squid:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "3.0"
},
{
"last_affected": "3.5.28"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:squid-cache:squid:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "4.0"
},
{
"fixed": "4.11"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:squid-cache:squid:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "5.0"
},
{
"fixed": "5.0.2"
}
],
"source": "CPE_RANGE"
},
{
"range": [
{
"fixed": "eeebf0f37a72a2de08348e85ae34b02c34e9a811"
}
],
"source": "REFERENCES_COMMIT"
}
]
}
}
],
"versions": [
"SQUID_5_0_1",
"SQUID_4_10",
"SQUID_4_9",
"SQUID_4_8",
"SQUID_4_7",
"M-staged-PR365",
"M-staged-PR370",
"M-staged-PR376",
"M-staged-PR375",
"SQUID_4_6",
"M-staged-PR373",
"M-staged-PR372",
"M-staged-PR319",
"M-staged-PR366",
"M-staged-PR351",
"M-staged-PR342",
"M-staged-PR364",
"M-staged-PR359",
"SQUID_4_5",
"M-staged-PR348",
"M-staged-PR345",
"SQUID_4_4",
"M-staged-PR314",
"SQUID_3_5_28",
"M-staged-PR306",
"SQUID_4_3",
"M-staged-PR294",
"M-staged-PR299",
"M-staged-PR295",
"M-staged-PR293",
"M-staged-PR164",
"SQUID_4_2",
"M-staged-PR276",
"M-staged-PR274",
"SQUID_3_5_27",
"M-staged-PR264",
"M-staged-PR268",
"M-staged-PR267",
"M-staged-PR266",
"M-staged-PR258",
"M-staged-PR230",
"M-staged-PR255",
"M-staged-PR252",
"M-staged-PR229",
"M-staged-PR241",
"M-staged-PR239",
"M-staged-PR242",
"SQUID_4_1",
"M-staged-PR235",
"M-staged-PR238",
"M-staged-PR218",
"M-staged-PR237",
"M-staged-PR227",
"M-staged-PR202",
"M-staged-PR225",
"SQUID_4_0_25",
"M-staged-PR220",
"M-staged-PR221",
"M-staged-PR210",
"M-staged-PR209",
"M-staged-PR208",
"M-staged-PR198",
"M-staged-PR206",
"M-staged-PR182",
"M-staged-PR195",
"M-staged-PR199",
"M-staged-PR200",
"M-staged-PR196",
"M-staged-PR193",
"M-staged-PR181",
"M-staged-PR189",
"M-staged-PR176",
"M-staged-PR186",
"SQUID_4_0_24",
"M-staged-PR179",
"M-staged-PR170",
"M-staged-PR161",
"SQUID_4_0_23",
"SQUID_4_0_22",
"SQUID_4_0_21",
"SQUID_3_5_26",
"SQUID_4_0_20",
"SQUID_3_5_25",
"SQUID_4_0_19",
"SQUID_3_5_24",
"SQUID_4_0_18",
"SQUID_3_5_23",
"SQUID_4_0_17",
"SQUID_4_0_16",
"SQUID_3_5_22",
"SQUID_4_0_15",
"SQUID_3_5_21",
"SQUID_4_0_14",
"SQUID_4_0_13",
"SQUID_3_5_20",
"SQUID_4_0_12",
"SQUID_4_0_11",
"SQUID_3_5_19",
"SQUID_4_0_10",
"SQUID_3_5_18",
"SQUID_3_5_17",
"SQUID_4_0_9",
"SQUID_3_5_16",
"SQUID_4_0_8",
"SQUID_3_5_15",
"SQUID_4_0_7",
"SQUID_3_5_14",
"SQUID_4_0_6",
"SQUID_4_0_5",
"SQUID_3_5_13",
"SQUID_4_0_4",
"SQUID_3_5_12",
"SQUID_4_0_3",
"SQUID_3_5_11",
"SQUID_4_0_2",
"SQUID_4_0_1",
"SQUID_3_5_10",
"SQUID_3_5_9",
"SQUID_3_5_8",
"SQUID_3_5_7",
"SQUID_3_5_6",
"SQUID_3_5_5",
"SQUID_3_5_4",
"SQUID_3_5_3",
"SQUID_3_5_2",
"SQUID_3_5_1",
"SQUID_3_5_0_4",
"SQUID_3_5_0_3",
"SQUID_3_5_0_2",
"SQUID_3_5_0_1",
"take00",
"SQUID_3_0_RC1",
"SQUID_3_0_PRE7",
"SQUID_3_0_PRE6",
"SQUID_3_0_PRE5",
"SQUID_3_0_PRE4",
"SQUID_3_0_PRE3",
"SQUID_3_0_PRE2",
"SQUID_3_0_PRE1",
"HISTORIC_RELEASES"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-11945.json",
"vanir_signatures": [
{
"id": "CVE-2020-11945-95d03fd5",
"digest": {
"length": 100,
"function_hash": "67694868943562031426867548165551445569"
},
"source": "https://github.com/squid-cache/squid/commit/eeebf0f37a72a2de08348e85ae34b02c34e9a811",
"target": {
"file": "src/auth/digest/Config.cc",
"function": "authDigestNonceLinks"
},
"deprecated": false,
"signature_type": "Function",
"signature_version": "v1"
},
{
"id": "CVE-2020-11945-9e904d95",
"digest": {
"threshold": 0.9,
"line_hashes": [
"312035431352774975245205945866455267692",
"127614888837209980977490773844017997328",
"135588185159393913533626977155847267680",
"102454058108144165087047766188167704255"
]
},
"source": "https://github.com/squid-cache/squid/commit/eeebf0f37a72a2de08348e85ae34b02c34e9a811",
"target": {
"file": "src/auth/digest/Config.h"
},
"deprecated": false,
"signature_type": "Line",
"signature_version": "v1"
},
{
"id": "CVE-2020-11945-cd931e67",
"digest": {
"threshold": 0.9,
"line_hashes": [
"338161685995787453028451825167785309475",
"140955325328919288341820778626349923389",
"4145077588753404222881979534001723466",
"110561542417632611016072614197889584810",
"129407750181244320020778213567084638291",
"228308081954307758122148219118506646516",
"202661084589309383047478172927329929327",
"124711009615817150745696439295484893323",
"71985290021380143159143221557628222363",
"339350136142636425663541903394561553847",
"288051683732187031973044283287329409022",
"258739234321288731406580467410176032181",
"330863924253968778429986951911762724958",
"211279373868081939640311278532833562852",
"78507472701961014960551386346382340872",
"250004226996742682635911950554513026132",
"84951658753368259976784305259451228665",
"80676065707016793651073899688758426989",
"325457318407040229138974783324638666926",
"100322358462259558893253727923964263608",
"176902589630817361748307934918769115416"
]
},
"source": "https://github.com/squid-cache/squid/commit/eeebf0f37a72a2de08348e85ae34b02c34e9a811",
"target": {
"file": "src/auth/digest/Config.cc"
},
"deprecated": false,
"signature_type": "Line",
"signature_version": "v1"
},
{
"id": "CVE-2020-11945-dd7cdc93",
"digest": {
"length": 187,
"function_hash": "133251268618066714835484527439919811976"
},
"source": "https://github.com/squid-cache/squid/commit/eeebf0f37a72a2de08348e85ae34b02c34e9a811",
"target": {
"file": "src/auth/digest/Config.cc",
"function": "authDigestNonceLink"
},
"deprecated": false,
"signature_type": "Function",
"signature_version": "v1"
}
],
"vanir_signatures_modified": "2026-10-24T14:22:37Z"
}
}
],
"modified": "2026-10-24T14:22:37.069875504Z",
"provider": "osv",
"references": [
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4FWQRYZJPHAZBLXJ56FPCHJN5X2FP3VA/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/H4MWXEZAJSOGRJSS2JCJK4WBSND4IV46/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RV2VZWFJNO3B56IVN56HHKJASG5DYUIX/",
"https://lists.debian.org/debian-lts-announce/2020/07/msg00009.html",
"https://security.gentoo.org/glsa/202005-05",
"https://security.netapp.com/advisory/ntap-20210304-0004/",
"https://usn.ubuntu.com/4356-1/",
"https://www.debian.org/security/2020/dsa-4682",
"https://bugzilla.suse.com/show_bug.cgi?id=1170313",
"https://github.com/squid-cache/squid/commit/eeebf0f37a72a2de08348e85ae34b02c34e9a811",
"https://github.com/squid-cache/squid/pull/585"
],
"provider_metadata": {
"unresolved_ranges": [
{
"cpes": [
"cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*",
"cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*",
"cpe:2.3:o:canonical:ubuntu_linux:19.10:*:*:*:*:*:*:*",
"cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:*"
],
"vendor_product": "canonical:ubuntu_linux",
"extracted_events": [
{
"range": [
{
"introduced": "16.04"
},
{
"last_affected": "16.04"
},
{
"introduced": "18.04"
},
{
"last_affected": "18.04"
},
{
"introduced": "19.10"
},
{
"last_affected": "19.10"
},
{
"introduced": "20.04"
},
{
"last_affected": "20.04"
}
],
"source": "CPE_STRING"
}
]
},
{
"cpes": [
"cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*",
"cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*"
],
"vendor_product": "debian:debian_linux",
"extracted_events": [
{
"range": [
{
"introduced": "9.0"
},
{
"last_affected": "9.0"
},
{
"introduced": "10.0"
},
{
"last_affected": "10.0"
}
],
"source": "CPE_STRING"
}
]
},
{
"cpes": [
"cpe:2.3:o:fedoraproject:fedora:30:*:*:*:*:*:*:*",
"cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*",
"cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*"
],
"vendor_product": "fedoraproject:fedora",
"extracted_events": [
{
"range": [
{
"introduced": "30"
},
{
"last_affected": "30"
},
{
"introduced": "31"
},
{
"last_affected": "31"
},
{
"introduced": "32"
},
{
"last_affected": "32"
}
],
"source": "CPE_STRING"
}
]
},
{
"cpes": [
"cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:*"
],
"vendor_product": "opensuse:leap",
"extracted_events": [
{
"range": [
{
"introduced": "15.1"
},
{
"last_affected": "15.1"
}
],
"source": "CPE_STRING"
}
]
}
]
}
},
"related_cves": [
{
"value": "CVE-2020-11945",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 443671,
"published_at": "2020-04-23T15:15:14.233+00:00"
}