High
Security advisory
Sudo through 1.8.29 allows local users to escalate to root if they have write access to file descriptor 3 of the sudo process. This occurs because of a race condition between determining a uid, and the setresuid and openat system calls. The attacker can write "ALL ALL=(ALL) NOPASSWD:ALL" to /proc/#####/fd/3 at a time when Sudo is prompting for a password. NOTE: This has been disputed due to the way Linux /proc works. It has been argued that writing to /proc/#####/fd/3 would only be viable if you had permission to write to /etc/sudoers. Even with write permission to /proc/#####/fd/3, it would not help you write to /etc/sudoers
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2019-18684
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 06:35 UTC · Revision 1
Source evidence
Sudo through 1.8.29 allows local users to escalate to root if they have write access to file descriptor 3 of the sudo process. This occurs because of a race condition between determining a uid, and the setresuid and openat system calls. The attacker can write "ALL ALL=(ALL) NOPASSWD:ALL" to /proc/#####/fd/3 at a time when Sudo is prompting for a password. NOTE: This has been disputed due to the way Linux /proc works. It has been argued that writing to /proc/#####/fd/3 would only be viable if you had permission to write to /etc/sudoers. Even with write permission to /proc/#####/fd/3, it would not help you write to /etc/sudoers
osv:CVE-2019-18684
Complete source record
{
"id": "b2d234e931bcf75a2db592d0aec378847e68ec55d93a375bddaf2c6d5e424c22",
"url": "https://osv.dev/vulnerability/CVE-2019-18684",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2019-18684",
"summary": "Sudo through 1.8.29 allows local users to escalate to root if they have write access to file descriptor 3 of the sudo process. This occurs because of a race condition between determining a uid, and the setresuid and openat system calls. The attacker can write \"ALL ALL=(ALL) NOPASSWD:ALL\" to /proc/#####/fd/3 at a time when Sudo is prompting for a password. NOTE: This has been disputed due to the way Linux /proc works. It has been argued that writing to /proc/#####/fd/3 would only be viable if you had permission to write to /etc/sudoers. Even with write permission to /proc/#####/fd/3, it would not help you write to /etc/sudoers",
"evidence": "osv:CVE-2019-18684",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2019-18684",
"aliases": [
"CVE-2019-18684"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/millert/sudo",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"last_affected": "6b83a6eee0bbbe654eb54d5a1fcf149ee1da173d"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:sudo_project:sudo:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "0"
},
{
"last_affected": "1.8.29"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"versions": [
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"SUDO_1_8_28",
"SUDO_1_8_27",
"SUDO_1_8_26",
"SUDO_1_8_25p1",
"SUDO_1_8_25",
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"SUDO_1_8_16",
"SUDO_1_8_15",
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"SUDO_1_8_11p2",
"SUDO_1_8_11p1",
"SUDO_1_8_11",
"SUDO_1_8_10p3",
"SUDO_1_8_10p2",
"SUDO_1_8_10p1",
"SUDO_1_8_10",
"SUDO_1_8_9p5",
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"SUDO_1_8_9",
"SUDO_1_8_8",
"SUDO_1_8_7",
"SUDO_1_8_6p8",
"SUDO_1_8_6p7",
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"SUDO_1_8_6p3",
"SUDO_1_8_6p2",
"SUDO_1_8_6p1",
"SUDO_1_8_6",
"SUDO_1_8_5p3",
"SUDO_1_8_5p2",
"SUDO_1_8_5p1",
"SUDO_1_8_5",
"SUDO_1_8_4p5",
"SUDO_1_8_4p4",
"SUDO_1_8_4p3",
"SUDO_1_8_4p2",
"SUDO_1_8_4p1",
"SUDO_1_8_4",
"SUDO_1_8_3",
"SUDO_1_8_2",
"SUDO_1_8_1",
"SUDO_1_8_0",
"SUDO_1_7_2",
"SUDO_1_7_1",
"SUDO_1_7_0",
"SUDO_1_6_8p1",
"SUDO_1_6_8",
"SUDO_1_6_7",
"SUDO_1_6_6",
"SUDO_1_6_5",
"SUDO_1_6_4",
"SUDO_1_6_3",
"SUDO_1_6_2",
"SUDO_1_6_1",
"SUDO_1_6_0",
"SUDO_1_5_9",
"SUDO_1_5_8",
"SUDO_1_5_7",
"SUDO_1_5_6",
"SUDO_1_5_4",
"SUDO_1_5_3",
"SUDO_1_5_2",
"SUDO_1_5_1",
"SUDO_1_5_0",
"SUDO_1_4_0",
"SUDO_1_3_1",
"SUDO_1_3_0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2019-18684.json"
}
},
{
"ranges": [
{
"repo": "https://github.com/sudo-project/sudo",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"last_affected": "6b83a6eee0bbbe654eb54d5a1fcf149ee1da173d"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:sudo_project:sudo:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "0"
},
{
"last_affected": "1.8.29"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"versions": [
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"SUDO_1_8_29",
"v1.8.28p1",
"SUDO_1_8_28p1",
"v1.8.28",
"SUDO_1_8_28",
"v1.8.27",
"SUDO_1_8_27",
"v1.8.26",
"SUDO_1_8_26",
"v1.8.25p1",
"SUDO_1_8_25p1",
"v1.8.25",
"SUDO_1_8_25",
"v1.8.24",
"SUDO_1_8_24",
"v1.8.23",
"SUDO_1_8_23",
"v1.8.22",
"SUDO_1_8_22",
"v1.8.21p2",
"SUDO_1_8_21p2",
"v1.8.21p1",
"SUDO_1_8_21p1",
"v1.8.21",
"SUDO_1_8_21",
"v1.8.20p2",
"SUDO_1_8_20p2",
"v1.8.20p1",
"SUDO_1_8_20p1",
"v1.8.20",
"SUDO_1_8_20",
"v1.8.19p2",
"SUDO_1_8_19p2",
"v1.8.19p1",
"SUDO_1_8_19p1",
"v1.8.19",
"SUDO_1_8_19",
"v1.8.18p1",
"SUDO_1_8_18p1",
"v1.8.18",
"SUDO_1_8_18",
"v1.8.17p1",
"SUDO_1_8_17p1",
"v1.8.17",
"SUDO_1_8_17",
"v1.8.16",
"SUDO_1_8_16",
"v1.8.15",
"SUDO_1_8_15",
"v1.8.14p3",
"SUDO_1_8_14p3",
"v1.8.14p1",
"SUDO_1_8_14p1",
"v1.8.14",
"SUDO_1_8_14",
"v1.8.13",
"SUDO_1_8_13",
"v1.8.12",
"SUDO_1_8_12",
"v1.8.11p2",
"SUDO_1_8_11p2",
"v1.8.11p1",
"SUDO_1_8_11p1",
"v1.8.11",
"SUDO_1_8_11",
"v1.8.10p3",
"SUDO_1_8_10p3",
"v1.8.10p2",
"SUDO_1_8_10p2",
"v1.8.10p1",
"SUDO_1_8_10p1",
"v1.8.10",
"SUDO_1_8_10",
"v1.8.9p5",
"SUDO_1_8_9p5",
"v1.8.9p4",
"SUDO_1_8_9p4",
"v1.8.9p3",
"SUDO_1_8_9p3",
"v1.8.9p2",
"SUDO_1_8_9p2",
"v1.8.9p1",
"SUDO_1_8_9p1",
"v1.8.9",
"SUDO_1_8_9",
"v1.8.8",
"SUDO_1_8_8",
"v1.8.7",
"SUDO_1_8_7",
"v1.8.6p8",
"SUDO_1_8_6p8",
"v1.8.6p7",
"SUDO_1_8_6p7",
"v1.8.6p6",
"SUDO_1_8_6p6",
"v1.8.6p5",
"SUDO_1_8_6p5",
"v1.8.6p4",
"SUDO_1_8_6p4",
"v1.8.6p3",
"SUDO_1_8_6p3",
"v1.8.6p2",
"SUDO_1_8_6p2",
"v1.8.6p1",
"SUDO_1_8_6p1",
"v1.8.6",
"SUDO_1_8_6",
"v1.8.5p3",
"SUDO_1_8_5p3",
"v1.8.5p2",
"SUDO_1_8_5p2",
"v1.8.5p1",
"SUDO_1_8_5p1",
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"v1.8.4p2",
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"SUDO_1_8_4p1",
"v1.8.4",
"SUDO_1_8_4",
"v1.8.3",
"SUDO_1_8_3",
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"SUDO_1_8_2",
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"SUDO_1_6_8p1",
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"SUDO_1_6_8",
"v1.6.7",
"SUDO_1_6_7",
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"SUDO_1_6_6",
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"SUDO_1_6_5",
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"SUDO_1_6_4",
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"SUDO_1_6_0",
"v1.5.9",
"SUDO_1_5_9",
"v1.5.8",
"SUDO_1_5_8",
"v1.5.7",
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"SUDO_1_5_6",
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"v1.4.0",
"SUDO_1_4_0",
"v1.3.1",
"SUDO_1_3_1",
"v1.3.0",
"SUDO_1_3_0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2019-18684.json"
}
}
],
"modified": "2026-10-24T10:30:41.545655119Z",
"provider": "osv",
"references": [
"https://gist.github.com/oxagast/51171aa161074188a11d96cbef884bbd"
],
"provider_metadata": {}
},
"related_cves": [
{
"value": "CVE-2019-18684",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 435177,
"published_at": "2019-11-04T16:15:11.437+00:00"
}