Medium
Security advisory
Symfony is a PHP framework for web and console applications and a set of reusable PHP components. The ability to enumerate users was possible without relevant permissions due to different handling depending on whether the user existed or not when attempting to use the switch users functionality. We now ensure that 403s are returned whether the user exists or not if a user cannot switch to a user or if the user does not exist. The patch for this issue is available for branch 3.4.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2021-21424
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 08:39 UTC · Revision 1
Source evidence
Symfony is a PHP framework for web and console applications and a set of reusable PHP components. The ability to enumerate users was possible without relevant permissions due to different handling depending on whether the user existed or not when attempting to use the switch users functionality. We now ensure that 403s are returned whether the user exists or not if a user cannot switch to a user or if the user does not exist. The patch for this issue is available for branch 3.4.
osv:CVE-2021-21424
Complete source record
{
"id": "2785a5fe964f5e8dc739b5f1944b2a61fb31a3788715b0d7341c3142bdb94812",
"url": "https://osv.dev/vulnerability/CVE-2021-21424",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2021-21424",
"summary": "Symfony is a PHP framework for web and console applications and a set of reusable PHP components. The ability to enumerate users was possible without relevant permissions due to different handling depending on whether the user existed or not when attempting to use the switch users functionality. We now ensure that 403s are returned whether the user exists or not if a user cannot switch to a user or if the user does not exist. The patch for this issue is available for branch 3.4.",
"evidence": "osv:CVE-2021-21424",
"products": [],
"severity": "medium",
"structured": {
"id": "CVE-2021-21424",
"aliases": [
"BIT-symfony-2021-21424",
"CVE-2021-21424",
"GHSA-5pv8-ppvj-4h68"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/symfony/security-http",
"type": "GIT",
"events": [
{
"introduced": "18f96c1f4aff294d6872908741731ff0993dbd6f"
},
{
"fixed": "c55a8f70fb2a04cf8ec3263d337abb3f22fc0132"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:sensiolabs:symfony:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "5.0.0"
},
{
"fixed": "5.2.8"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-21424.json"
}
},
{
"ranges": [
{
"repo": "https://github.com/symfony/symfony",
"type": "GIT",
"events": [
{
"introduced": "5615b92cd452cd54f1433a3f53de87c096a1107f"
},
{
"fixed": "d0d17db1c5e0497e66afe99e920b787aebee5f0a"
},
{
"introduced": "26ca7023b1c45dce951da7206ed70049267d27bc"
},
{
"fixed": "bb7ec823d2ea5a77c83a11739fc38f62e2b7999c"
},
{
"introduced": "ea815ba986fe3be54acb5a47b0dc8760cf54e31d"
},
{
"fixed": "23147f993c63c9eaafe3fa7ac0363a2e42d66a22"
},
{
"fixed": "2a581d22cc621b33d5464ed65c4bc2057f72f011"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:sensiolabs:symfony:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "2.8.0"
},
{
"fixed": "3.4.48"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:sensiolabs:symfony:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "4.0.0"
},
{
"fixed": "4.4.23"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:sensiolabs:symfony:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "5.0.0"
},
{
"fixed": "5.2.8"
}
],
"source": "CPE_RANGE"
},
{
"range": [
{
"fixed": "2a581d22cc621b33d5464ed65c4bc2057f72f011"
}
],
"source": "REFERENCES_COMMIT"
}
]
}
}
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-21424.json"
}
}
],
"modified": "2026-10-24T10:47:52.914734024Z",
"provider": "osv",
"references": [
"https://lists.debian.org/debian-lts-announce/2023/07/msg00014.html",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KENRNLB3FYXYGDWRBH2PDBOZZKOD7VY4/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RH7TMM5CHQYBFFGXWRPJDPB3SKCZXI2M/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UC7BND775DVZDQT3RMGD2HVB2PKLJDJW/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VRUS2H2SSOQWNLBD35SKIWIDQEMV2PD3/",
"https://github.com/symfony/symfony/commit/2a581d22cc621b33d5464ed65c4bc2057f72f011",
"https://github.com/symfony/symfony/security/advisories/GHSA-5pv8-ppvj-4h68"
],
"provider_metadata": {
"unresolved_ranges": [
{
"cpes": [
"cpe:2.3:a:sensiolabs:symfony:*:*:*:*:*:*:*:*"
],
"vendor_product": "sensiolabs:symfony",
"extracted_events": [
{
"range": [
{
"introduced": "2.8.0"
},
{
"fixed": "3.4.48"
},
{
"introduced": "4.0.0"
},
{
"fixed": "4.4.23"
}
],
"source": "CPE_RANGE"
}
]
},
{
"cpes": [
"cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*",
"cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*"
],
"vendor_product": "fedoraproject:fedora",
"extracted_events": [
{
"range": [
{
"introduced": "33"
},
{
"last_affected": "33"
},
{
"introduced": "34"
},
{
"last_affected": "34"
}
],
"source": "CPE_STRING"
}
]
}
]
}
},
"related_cves": [
{
"value": "CVE-2021-21424",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 441596,
"published_at": "2021-05-13T16:15:07.777+00:00"
}