CVE catalog

CVE-2021-33646

libtar vulnerabilities

A flaw was found in libtar. This security vulnerability occurs because the th_read() function in libtar doesn’t free a variable t->th_buf.gnu_longname after allocating memory, which may cause a memory leak. libtar: memory leak found in th_read() function The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Severity: High · CVSS 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published: Jan 1, 2021, 12:00:00 AM UTC
Source: [NVD] · [CVE record]
EPSS: 2.00% · Oct 27, 2026

Projects and upstream resources

[libtar][Source-reported homepage]

Reported versions and fixes

Each observation applies to its named package, distribution, and release. Distribution backports can fix a vulnerability while retaining an older upstream version number.

Distribution / release	Package	Version	Status	Source
Debianbookworm	libtar	`1.2.20-8+deb12u1`	FixedDistribution-reported fixed boundary	[CVE-2021-33646]

Showing 1 fix observations. All 15 observations, including unknown and conflicting reports, are available below.

Provider details and historical evidence

Distribution / release	Package	Version	Status	Source
UnknownRelease not reported	libtar	`1.2.20-8.1ubuntu0.24.04.1`	UnknownSource applicability is not established	Provider not reported
UnknownRelease not reported	libtar-dev	`1.2.20-8.1ubuntu0.24.04.1`	UnknownSource applicability is not established	Provider not reported
UnknownRelease not reported	libtar0t64	`1.2.20-8.1ubuntu0.24.04.1`	UnknownSource applicability is not established	Provider not reported
Debianbookworm	libtar	`1.2.20-8+deb12u1`	FixedDistribution-reported fixed boundary	[CVE-2021-33646]
Ubuntu20.04	libtar	`1.2.20-7`	UnknownSource applicability is not established	[UBUNTU-CVE-2021-33646]Apr 22, 2026, 12:54:28 PM UTC
Ubuntu20.04	libtar	`1.2.20-8`	UnknownSource applicability is not established	[UBUNTU-CVE-2021-33646]Apr 22, 2026, 12:54:28 PM UTC
Ubuntu20.04	libtar	`1.2.20-8ubuntu0.20.04.1`	UnknownSource applicability is not established	[UBUNTU-CVE-2021-33646]Apr 22, 2026, 12:54:28 PM UTC
Ubuntu22.04	libtar	`1.2.20-8`	UnknownSource applicability is not established	[UBUNTU-CVE-2021-33646]Apr 22, 2026, 12:54:28 PM UTC
Ubuntu22.04	libtar	`1.2.20-8ubuntu0.22.04.1`	UnknownSource applicability is not established	[UBUNTU-CVE-2021-33646]Apr 22, 2026, 12:54:28 PM UTC
Ubuntu24.04	libtar	`1.2.20-8`	UnknownSource applicability is not established	[UBUNTU-CVE-2021-33646]Apr 22, 2026, 12:54:28 PM UTC
Ubuntu24.04	libtar	`1.2.20-8.1`	UnknownSource applicability is not established	[UBUNTU-CVE-2021-33646]Apr 22, 2026, 12:54:28 PM UTC
Ubuntu24.04	libtar	`1.2.20-8.1build1`	UnknownSource applicability is not established	[UBUNTU-CVE-2021-33646]Apr 22, 2026, 12:54:28 PM UTC
Ubuntu24.04	libtar	`1.2.20-8.1ubuntu0.24.04.1`	UnknownSource applicability is not established	[UBUNTU-CVE-2021-33646]Apr 22, 2026, 12:54:28 PM UTC
Ubuntupro	libtar	`1.2.20-7`	UnknownSource applicability is not established	[UBUNTU-CVE-2021-33646]Apr 22, 2026, 12:54:28 PM UTC
Ubuntupro	libtar	`1.2.20-7ubuntu0.1~esm1`	UnknownSource applicability is not established	[UBUNTU-CVE-2021-33646]Apr 22, 2026, 12:54:28 PM UTC

Original provider fields

{
  "package_releases": [
    {
      "name": "libtar",
      "status": "fixed",
      "release": "bookworm",
      "version": "1.2.20-8+deb12u1"
    }
  ],
  "fixed_versions": [
    {
      "bug": null,
      "name": "libtar",
      "type": "source",
      "origin": null,
      "release": "bookworm",
      "urgency": "not yet assigned",
      "fixed_version": "1.2.20-8+deb12u1"
    }
  ],
  "distribution_packages": [
    {
      "name": "libtar",
      "fixed_version": "1.2.20-8.1ubuntu0.24.04.1",
      "applicability_unknown": true
    },
    {
      "name": "libtar-dev",
      "fixed_version": "1.2.20-8.1ubuntu0.24.04.1",
      "applicability_unknown": true
    },
    {
      "name": "libtar0t64",
      "fixed_version": "1.2.20-8.1ubuntu0.24.04.1",
      "applicability_unknown": true
    },
    {
      "name": "libtar",
      "distro": "ubuntu",
      "ranges": [
        {
          "type": "ECOSYSTEM",
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.2.20-7ubuntu0.1~esm1"
            }
          ]
        }
      ],
      "release": "pro",
      "versions": [
        "1.2.20-7"
      ],
      "ecosystem": "deb",
      "provider_url": "https://osv.dev/vulnerability/UBUNTU-CVE-2021-33646",
      "fixed_version": "1.2.20-7ubuntu0.1~esm1",
      "provider_source": "pypi",
      "provider_record_id": "UBUNTU-CVE-2021-33646",
      "provider_updated_at": "2026-04-22T12:54:28.144188Z",
      "applicability_unknown": true
    },
    {
      "name": "libtar",
      "distro": "ubuntu",
      "ranges": [
        {
          "type": "ECOSYSTEM",
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.2.20-8ubuntu0.20.04.1"
            }
          ]
        }
      ],
      "release": "20.04",
      "versions": [
        "1.2.20-7",
        "1.2.20-8"
      ],
      "ecosystem": "deb",
      "provider_url": "https://osv.dev/vulnerability/UBUNTU-CVE-2021-33646",
      "fixed_version": "1.2.20-8ubuntu0.20.04.1",
      "provider_source": "pypi",
      "provider_record_id": "UBUNTU-CVE-2021-33646",
      "provider_updated_at": "2026-04-22T12:54:28.144188Z",
      "applicability_unknown": true
    },
    {
      "name": "libtar",
      "distro": "ubuntu",
      "ranges": [
        {
          "type": "ECOSYSTEM",
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.2.20-8ubuntu0.22.04.1"
            }
          ]
        }
      ],
      "release": "22.04",
      "versions": [
        "1.2.20-8"
      ],
      "ecosystem": "deb",
      "provider_url": "https://osv.dev/vulnerability/UBUNTU-CVE-2021-33646",
      "fixed_version": "1.2.20-8ubuntu0.22.04.1",
      "provider_source": "pypi",
      "provider_record_id": "UBUNTU-CVE-2021-33646",
      "provider_updated_at": "2026-04-22T12:54:28.144188Z",
      "applicability_unknown": true
    },
    {
      "name": "libtar",
      "distro": "ubuntu",
      "ranges": [
        {
          "type": "ECOSYSTEM",
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.2.20-8.1ubuntu0.24.04.1"
            }
          ]
        }
      ],
      "release": "24.04",
      "versions": [
        "1.2.20-8",
        "1.2.20-8.1",
        "1.2.20-8.1build1"
      ],
      "ecosystem": "deb",
      "provider_url": "https://osv.dev/vulnerability/UBUNTU-CVE-2021-33646",
      "fixed_version": "1.2.20-8.1ubuntu0.24.04.1",
      "provider_source": "pypi",
      "provider_record_id": "UBUNTU-CVE-2021-33646",
      "provider_updated_at": "2026-04-22T12:54:28.144188Z",
      "applicability_unknown": true
    }
  ]
}

OpenFactory catalog packages

Matching against OpenFactory catalog package versions is in progress.

[Debian 12 (Bookworm)]

[libtar0]Unknown
Source package: [libtar]
Details (2)
- 1.2.20-8+deb12u1 · amd64 · bookworm
  Fixed · Fixed: 1.2.20-8+deb12u1
  usn · libtar · debian · bookworm; usn · libtar · debian · 12
- 1.2.20-8+deb12u1 · arm64 · bookworm
  Fixed · Fixed: 1.2.20-8+deb12u1
  usn · libtar · debian · bookworm; usn · libtar · debian · 12
[libtar-dev]Unknown
Source package: [libtar]
Details (2)
- 1.2.20-8+deb12u1 · amd64 · bookworm
  Fixed · Fixed: 1.2.20-8+deb12u1
  usn · libtar · debian · bookworm; usn · libtar · debian · 12
- 1.2.20-8+deb12u1 · arm64 · bookworm
  Fixed · Fixed: 1.2.20-8+deb12u1
  usn · libtar · debian · bookworm; usn · libtar · debian · 12

Observed: Oct 23, 2026, 5:57:54 PM UTC

References

[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX] · [Ubuntu Security Notices (USN)]