CVE-2020-36193: PEAR Archive_Tar Improper Link Resolution Vulnerability

Patch now

HIGH 7.5EXPLOITEDREMOTEWATCHLISTUPGRADEMITIGATEMITIGATE

CVE-2020-36193 is a high-severity flaw (CVSS 7.5) affecting archive tar, fedora, debian linux, reported as exploited in the wild. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

High severity
EPSS top 1%: very likely to be exploited
Exploited in the wild (CISA KEV)
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	70.6% (top 1%)
CISA exploited list	Yes, fix due 2022-09-15
Weakness	CWE-22, CWE-59
Published	2021-01-18
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: debian · drupal · fedoraproject · php

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-01-18 20:15 UTCPublished CVE record published
2022-08-25Exploited Added to the CISA Known Exploited Vulnerabilities list
2022-09-15Deadline CISA due date for US federal agencies to patch
2026-06-17 03:14 UTCUpdated Record last modified

php archive tar UPGRADE

Affected: <= 1.4.11

Fixed in: newer than 1.4.11

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy archive-tar || rpm -q archive-tar || archive-tar --version

2. UPGRADE to newer than 1.4.11 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade archive-tar

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade archive-tar

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

fedoraproject fedora MITIGATE

Affected: 32 · 33 · 34 · 35

Fixed in: no fixed release known

Safe to downgrade to: a release before 32

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

debian debian linux MITIGATE

Affected: 9.0 · 10.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 9.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

drupal drupal UPGRADE

Affected: >= 7.0 and < 7.78 · >= 8.9.0 and < 8.9.13 · >= 9.0.0 and < 9.0.11 · >= 9.1.0 and < 9.1.3

Fixed in: 7.78, 8.9.13, 9.0.11, 9.1.3

Safe to downgrade to: a release before 7.0

1. Check installed version

apt-cache policy drupal || rpm -q drupal || drupal --version

2. UPGRADE to 7.78 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade drupal

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade drupal

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 7.0 (Debian / Ubuntu)

apt-cache madison drupal sudo apt install drupal=<VERSION_BEFORE_7.0> sudo apt-mark hold drupal

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list drupal sudo dnf downgrade drupal-<VERSION_BEFORE_7.0> sudo dnf versionlock add drupal

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Exact fixes by distribution

A distro patch exists: prefer upgrading over downgrading.

Composer (PHP) · pear/archive_tar · FIXED · 1.4.13 · vulnerable: <= 1.4.11 · source

composer require "pear/archive_tar:>=1.4.13"

Fedora 46 · feh · FIXED · 3.13.1-1.fc46 · FEDORA-2026-3c76a13a4f · source

sudo dnf upgrade --advisory=FEDORA-2026-3c76a13a4f

Fedora ELN · setroubleshoot · FIXED · 3.3.37-7.eln159 · FEDORA-2026-f81b122fe1 · source

sudo dnf upgrade --advisory=FEDORA-2026-f81b122fe1

Ubuntu 20.04 · php-pear · FIXED · 1:1.10.9+submodules+notgz-1ubuntu0.20.04.2

sudo apt update && sudo apt install --only-upgrade php-pear dpkg --compare-versions "$(dpkg-query -W -f='${Version}' php-pear)" ge "1:1.10.9+submodules+notgz-1ubuntu0.20.04.2" && echo PATCHED || echo STILL-VULNERABLE

Debian 12 · php-pear · FIXED · 1:1.10.12+submodules+notgz+20210212-1

sudo apt update && sudo apt install --only-upgrade php-pear dpkg --compare-versions "$(dpkg-query -W -f='${Version}' php-pear)" ge "1:1.10.12+submodules+notgz+20210212-1" && echo PATCHED || echo STILL-VULNERABLE

Debian 13 · php-pear · FIXED · 1:1.10.12+submodules+notgz+20210212-1

RHEL 7 · php-pear · FIXED · php-pear-1.9.4-23.el7_9

sudo dnf upgrade --advisory=RHSA-2022:7340 rpm -q php-pear

RHEL 6 · php-pear · DEFERRED

RHEL 8 · php:7.2/php-pear · DEFERRED

RHEL 8 · php:7.3/php-pear · DEFERRED

RHEL 9 · php-pear · NOT AFFECTED

Alpine 3.20 · drupal7 · FIXED · drupal7-7.78-r0

apk add --upgrade drupal7 apk info -v drupal7

Amazon Linux 2 · see advisory · FIXED · ALAS2-2021-1602 · source

sudo yum update --advisory=ALAS2-2021-1602

Amazon Linux 1 · see advisory · FIXED · ALAS-2021-1481 · source

sudo yum update --advisory=ALAS-2021-1481

Verify at the official source NVD · CVE Program · CISA KEV catalog · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2020-36193?

archive tar: upgrade to newer than 1.4.11; fedora: mitigate or apply the listed mitigation; debian linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2020-36193 being exploited?

Yes. CVE-2020-36193 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

What does CVE-2020-36193 affect?

CVE-2020-36193 affects archive tar, fedora, debian linux. Severity is high (CVSS 7.5). 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.

How urgent is CVE-2020-36193?

Priority 86/100. High severity; EPSS top 1%: very likely to be exploited; Exploited in the wild (CISA KEV); Remotely exploitable, no login, no user action; On your watchlist

Software pages

Drupal vulnerabilities · PHP vulnerabilities · Debian vulnerabilities

Related CVEs

CVE-2021-32610 HIGH 7.1 UPGRADE MITIGATE In Archive_Tar before 1.4.14, symlinks can refer to targets outside of the extracted archive, a different vuln
CVE-2020-28949 HIGH 7.8 EXPLOITED UPGRADE MITIGATE PEAR Archive_Tar Deserialization of Untrusted Data Vulnerability
CVE-2020-28948 HIGH 7.8 UPGRADE MITIGATE Archive_Tar through 1.4.10 allows an unserialization attack because phar: is blocked but PHAR: is not blocked.

References

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