High
tmate-ssh-server — security advisory
World-writable permissions on the /tmp/tmate/sessions directory in tmate-ssh-server 2.3.0 allow a local attacker to compromise the integrity of session handling, or obtain the read-write session ID from a read-only session symlink in this directory.
- Products
- tmate-ssh-server
- Affected versions
- 2.3.0-49-g97d20249-1, 2.3.0-68-gd7334ee4-1, 2.3.0-68-gd7334ee4-1build1, 2.3.0-68-gd7334ee4-2, 2.3.0-68-gd7334ee4-2build1
- Fixed versions
- Not specified
- CVEs
- CVE-2021-44512
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 00:36 UTC · Revision 1
Source evidence
World-writable permissions on the /tmp/tmate/sessions directory in tmate-ssh-server 2.3.0 allow a local attacker to compromise the integrity of session handling, or obtain the read-write session ID from a read-only session symlink in this directory.
osv:UBUNTU-CVE-2021-44512
tmate-ssh-server
Fixed versions: Not specified
tmate-ssh-server
Fixed versions: Not specified
tmate-ssh-server
Fixed versions: Not specified
tmate-ssh-server
Fixed versions: Not specified
tmate-ssh-server
Fixed versions: Not specified
Complete source record
{
"id": "217018162c495f042fe386309507ffc9beb22e6807e8ce44a479105e80ff5346",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2021-44512",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2021-44512",
"summary": "World-writable permissions on the /tmp/tmate/sessions directory in tmate-ssh-server 2.3.0 allow a local attacker to compromise the integrity of session handling, or obtain the read-write session ID from a read-only session symlink in this directory.",
"evidence": "osv:UBUNTU-CVE-2021-44512",
"products": [
{
"name": {
"value": "tmate-ssh-server",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "2.3.0-49-g97d20249-1",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "tmate-ssh-server",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "2.3.0-68-gd7334ee4-1",
"evidence": "/affected/1/versions"
},
{
"value": "2.3.0-68-gd7334ee4-1build1",
"evidence": "/affected/1/versions"
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{
"name": {
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"evidence": "/affected/2/package/name"
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"evidence": "/affected/2/versions"
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{
"name": {
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"evidence": "/affected/4/package/name"
},
"prerequisites": [],
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"affected_versions": [
{
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"evidence": "/affected/4/versions"
},
{
"value": "2.3.0-68-gd7334ee4-2build1",
"evidence": "/affected/4/versions"
}
]
}
],
"severity": "high",
"structured": {
"id": "UBUNTU-CVE-2021-44512",
"aliases": [
"UBUNTU-CVE-2021-44512"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H"
},
{
"type": "Ubuntu",
"score": "medium"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "tmate-ssh-server",
"purl": "pkg:deb/ubuntu/tmate-ssh-server?arch=source&distro=jammy",
"ecosystem": "Ubuntu:22.04:LTS"
},
"versions": [
"2.3.0-49-g97d20249-1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-44512.json"
},
"ecosystem_specific": {
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{
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"package": {
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"purl": "pkg:deb/ubuntu/tmate-ssh-server?arch=source&distro=noble",
"ecosystem": "Ubuntu:24.04:LTS"
},
"versions": [
"2.3.0-68-gd7334ee4-1",
"2.3.0-68-gd7334ee4-1build1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-44512.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "tmate-ssh-server",
"binary_version": "2.3.0-68-gd7334ee4-1build1"
}
]
}
},
{
"ranges": [
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"package": {
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"purl": "pkg:deb/ubuntu/tmate-ssh-server?arch=source&distro=questing",
"ecosystem": "Ubuntu:25.10"
},
"versions": [
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"database_specific": {
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},
"ecosystem_specific": {
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{
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]
}
},
{
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"package": {
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"purl": "pkg:deb/ubuntu/tmate-ssh-server?arch=source&distro=stonking",
"ecosystem": "Ubuntu:26.10"
},
"versions": [
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],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-44512.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "tmate-ssh-server",
"binary_version": "2.3.0-68-gd7334ee4-2build1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
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],
"package": {
"name": "tmate-ssh-server",
"purl": "pkg:deb/ubuntu/tmate-ssh-server?arch=source&distro=resolute",
"ecosystem": "Ubuntu:26.04:LTS"
},
"versions": [
"2.3.0-68-gd7334ee4-2",
"2.3.0-68-gd7334ee4-2build1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-44512.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "tmate-ssh-server",
"binary_version": "2.3.0-68-gd7334ee4-2build1"
}
]
}
}
],
"modified": "2026-10-17T12:55:49.830853937Z",
"provider": "osv",
"upstream": [
"CVE-2021-44512"
],
"references": [
"https://ubuntu.com/security/CVE-2021-44512",
"https://www.openwall.com/lists/oss-security/2021/12/06/2",
"https://bugzilla.suse.com/show_bug.cgi?id=1189388",
"https://github.com/tmate-io/tmate-ssh-server/commit/1c020d1f5ca462f5b150b46a027aaa1bbe3c9596",
"https://www.cve.org/CVERecord?id=CVE-2021-44512"
]
},
"related_cves": [
{
"value": "CVE-2021-44512",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 354123,
"published_at": "2021-12-07T03:15:00+00:00"
}