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Actively exploited in the wild. This CVE is on the CISA Known Exploited Vulnerabilities list — treat remediation as urgent. Federal remediation due by 15 Sep 2022.
Archive TarApplication · PHP

CVE-2020-36193

HIGH · 7.5 CVSS v3.1 Published 2021-01-18
Fix available
A fix is available. Upgrade to 7.78 / 8.9.13 or later.
See remediation →
100/100
Remediation priority · Urgent
In the wild High EPSS Remotely reachable No privileges Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Tar.php in Archive_Tar through 1.4.11 allows write operations with Directory Traversal due to inadequate checking of symbolic links, a related issue to CVE-2020-28948.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

The Archive_Tar PHP library (Tar.php) through version 1.4.11 contains a directory traversal vulnerability during file extraction. The library inadequately validates symbolic links, allowing attackers to write files outside the intended extraction directory via specially crafted tar archives containing symlinks that point to arbitrary locations.

MitigationUpdate Archive_Tar to version 1.4.12 or later to obtain the patched version. Verify all extraction operations occur within intended directories and consider implementing additional path validation checks in code that uses this library.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Archive TarApplication
Affected:<= 1.4.11
FedoraOperating system
Affected:= 32= 33= 34= 35
Debian LinuxOperating system
Affected:= 9.0= 10.0
DrupalCMS
Affected:>= 7.0, < 7.78>= 8.9.0, < 8.9.13>= 9.0.0, < 9.0.11>= 9.1.0, < 9.1.3

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Locate the Archive_Tar library in your environment
    Search for Tar.php in your codebase or vendor directories. Common paths include vendor/pear/archive_tar/Tar.php, or within Drupal's vendor/ directory. Run: find . -name 'Tar.php' -path '*archive_tar*' 2>/dev/null
    Affected if The file exists and its version is 1.4.11 or earlier based on the version string inside the file
  2. Check the Archive_Tar version number
    Open the Tar.php file and search for a version definition (commonly 'VERSION' or '@version' comment). Compare the found version against the affected range: <= 1.4.11 is vulnerable
    Affected if The version string shows 1.4.11 or any version lower than 1.4.12
  3. Identify if Drupal is in use and its version
    Check for the presence of Drupal by looking for index.php or core/includes/bootstrap.inc. Determine the Drupal version by inspecting core/lib/Drupal.php or CHANGELOG.txt for version numbers
    Affected if Drupal versions are 7.0-7.77, 8.9.0-8.9.12, 9.0.0-9.0.10, or 9.1.0-9.1.2 (all vulnerable to this CVE through Archive_Tar inclusion)
  4. Determine if Fedora or Debian systems are in use
    Check the operating system by running: cat /etc/os-release (Fedora: VERSION_ID 32-35; Debian: VERSION_ID 9 or 10)
    Affected if The system runs Fedora 32, 33, 34, or 35, or Debian 9.0 or 10.0, which ship the vulnerable Archive_Tar package

Your environment is affected if Archive_Tar version is 1.4.11 or lower, or if you run vulnerable Drupal/Fedora/Debian versions that bundle this library, and you perform extraction operations using the library.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 7.78 / 8.9.13 / 9.0.11 or later
Fixed in 7.788.9.139.0.11
Vendor patch github.com →
Interim mitigation

Update Archive_Tar to version 1.4.12 or later to obtain the patched version. Verify all extraction operations occur within intended directories and consider implementing additional path validation checks in code that uses this library.

Recommended fix High confidence

Archive_Tar 1.4.12 or later / Drupal 7.78+ / Drupal 8.9.13+ / Drupal 9.0.11+ / Drupal 9.1.3+

  1. Identify the Archive_Tar package in your project (usually via composer or PEAR)
  2. Run `pear upgrade Archive_Tar` to upgrade to the latest version, or if using Composer run `composer update pear/archive_tar`
  3. Verify the upgrade was successful by checking the version: `pear list Archive_Tar` or checking the installed version in your vendor directory
  4. If using Drupal, apply the appropriate Drupal security update: 7.78, 8.9.13, 9.0.11, or 9.1.3 depending on your version branch
  5. After upgrading, test that tar extraction functionality still works correctly in your application

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Archive Tar Exploited in the wild — priority engagement
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing4.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,360
Get it fixed fast

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,176.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2020-36193 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data