Security advisory
An issue was discovered in shadow 4.5. newgidmap (in shadow-utils) is setuid and allows an unprivileged user to be placed in a user namespace where setgroups(2) is permitted. This allows an attacker to remove themselves from a supplementary group, which may allow access to certain filesystem paths if the administrator has used "group blacklisting" (e.g., chmod g-rwx) to restrict access to paths. This flaw effectively reverts a security feature in the kernel (in particular, the /proc/self/setgroups knob) to prevent this sort of privilege escalation.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2018-7169
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 05:06 UTC · Revision 1
Source evidence
An issue was discovered in shadow 4.5. newgidmap (in shadow-utils) is setuid and allows an unprivileged user to be placed in a user namespace where setgroups(2) is permitted. This allows an attacker to remove themselves from a supplementary group, which may allow access to certain filesystem paths if the administrator has used "group blacklisting" (e.g., chmod g-rwx) to restrict access to paths. This flaw effectively reverts a security feature in the kernel (in particular, the /proc/self/setgroups knob) to prevent this sort of privilege escalation.
osv:CVE-2018-7169
Complete source record
{
"id": "7c1ec7513f6fcc4e3c0377d75fbeb80d38fb6ad4f88ce240a20bb5861104e217",
"url": "https://osv.dev/vulnerability/CVE-2018-7169",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2018-7169",
"summary": "An issue was discovered in shadow 4.5. newgidmap (in shadow-utils) is setuid and allows an unprivileged user to be placed in a user namespace where setgroups(2) is permitted. This allows an attacker to remove themselves from a supplementary group, which may allow access to certain filesystem paths if the administrator has used \"group blacklisting\" (e.g., chmod g-rwx) to restrict access to paths. This flaw effectively reverts a security feature in the kernel (in particular, the /proc/self/setgroups knob) to prevent this sort of privilege escalation.",
"evidence": "osv:CVE-2018-7169",
"products": [],
"severity": "medium",
"structured": {
"id": "CVE-2018-7169",
"aliases": [
"CVE-2018-7169"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/shadow-maint/shadow",
"type": "GIT",
"events": [
{
"introduced": "15be89f89d553c06d52453721ee8e9a8433cfdfd"
},
{
"last_affected": "15be89f89d553c06d52453721ee8e9a8433cfdfd"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:shadow_project:shadow:4.5:*:*:*:*:*:*:*",
"range": [
{
"introduced": "4.5"
},
{
"last_affected": "4.5"
}
],
"source": "CPE_STRING"
}
]
}
}
],
"versions": [
"4.5"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2018-7169.json"
}
}
],
"modified": "2026-10-24T10:30:24.784008331Z",
"provider": "osv",
"references": [
"https://security.gentoo.org/glsa/201805-09",
"https://bugs.launchpad.net/ubuntu/+source/shadow/+bug/1729357"
],
"provider_metadata": {}
},
"related_cves": [
{
"value": "CVE-2018-7169",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 431215,
"published_at": "2018-02-15T20:29:00.867+00:00"
}