Security advisory
An issue was discovered in Squid through 4.7. When handling requests from users, Squid checks its rules to see if the request should be denied. Squid by default comes with rules to block access to the Cache Manager, which serves detailed server information meant for the maintainer. This rule is implemented via url_regex. The handler for url_regex rules URL decodes an incoming request. This allows an attacker to encode their URL to bypass the url_regex check, and gain access to the blocked resource.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2019-12524
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 08:01 UTC · Revision 1
Source evidence
An issue was discovered in Squid through 4.7. When handling requests from users, Squid checks its rules to see if the request should be denied. Squid by default comes with rules to block access to the Cache Manager, which serves detailed server information meant for the maintainer. This rule is implemented via url_regex. The handler for url_regex rules URL decodes an incoming request. This allows an attacker to encode their URL to bypass the url_regex check, and gain access to the blocked resource.
osv:CVE-2019-12524
Complete source record
{
"id": "93ece4ef9a6adeb93d5ad0e1f517181f0b95d21369788c0ab6dc5e597c76ac42",
"url": "https://osv.dev/vulnerability/CVE-2019-12524",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2019-12524",
"summary": "An issue was discovered in Squid through 4.7. When handling requests from users, Squid checks its rules to see if the request should be denied. Squid by default comes with rules to block access to the Cache Manager, which serves detailed server information meant for the maintainer. This rule is implemented via url_regex. The handler for url_regex rules URL decodes an incoming request. This allows an attacker to encode their URL to bypass the url_regex check, and gain access to the blocked resource.",
"evidence": "osv:CVE-2019-12524",
"products": [],
"severity": "critical",
"structured": {
"id": "CVE-2019-12524",
"aliases": [
"CVE-2019-12524"
],
"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": "2e17b02616d37206ba9cccc53c20667624fbef9f"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:squid-cache:squid:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "0"
},
{
"last_affected": "4.7"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"versions": [
"SQUID_4_7",
"SQUID_4_6",
"SQUID_4_5",
"SQUID_4_4",
"SQUID_4_3",
"SQUID_4_2",
"SQUID_4_1",
"SQUID_4_0_25",
"SQUID_4_0_24",
"SQUID_4_0_23",
"SQUID_4_0_22",
"SQUID_4_0_21",
"SQUID_4_0_20",
"SQUID_4_0_19",
"SQUID_4_0_18",
"SQUID_4_0_17",
"SQUID_4_0_16",
"SQUID_4_0_15",
"SQUID_4_0_14",
"SQUID_4_0_13",
"SQUID_4_0_12",
"SQUID_4_0_11",
"SQUID_4_0_10",
"SQUID_4_0_9",
"SQUID_4_0_8",
"SQUID_4_0_7",
"SQUID_4_0_6",
"SQUID_4_0_5",
"SQUID_4_0_4",
"SQUID_4_0_3",
"SQUID_4_0_2",
"SQUID_4_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-2019-12524.json"
}
}
],
"modified": "2026-10-24T10:31:01.912760935Z",
"provider": "osv",
"references": [
"https://gitlab.com/jeriko.one/security/-/blob/master/squid/CVEs/CVE-2019-12524.txt",
"https://lists.debian.org/debian-lts-announce/2020/07/msg00009.html",
"https://security.netapp.com/advisory/ntap-20210205-0006/",
"https://usn.ubuntu.com/4446-1/",
"https://www.debian.org/security/2020/dsa-4682"
],
"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:*:*:*"
],
"vendor_product": "canonical:ubuntu_linux",
"extracted_events": [
{
"range": [
{
"introduced": "16.04"
},
{
"last_affected": "16.04"
},
{
"introduced": "18.04"
},
{
"last_affected": "18.04"
}
],
"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"
}
]
}
]
}
},
"related_cves": [
{
"value": "CVE-2019-12524",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 439896,
"published_at": "2020-04-15T19:15:12.533+00:00"
}