CVE-2020-28949

medium KEV

Published 2020-11-25 · Modified 2022-08-25

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CVSS v3

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

CVSS v4 NEW

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not yet in upstream

VIR risk

8.0

Description

PEAR Archive_Tar allows an unserialization attack because phar: is blocked but PHAR: is not blocked. PEAR stands for PHP Extension and Application Repository and it is an open-source framework and distribution system for reusable PHP components with known usage in third-party products such as Drupal Core and Red Hat Linux.

CISA KEV

Vendor: PEAR
Product: Archive_Tar
Due date: 2022-09-15

Predictions

Exploit likelihood

99%

Patch ETA

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Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

Exploits

Public proof-of-concept code below. AS-IS, for defenders and authorised testing only.

Metasploit modules

exploit_multi/fileformat/archive_tar_arb_file_write rank 600

PEAR Archive_Tar 1.4.10 Arbitrary File Write

Source fetch failed: fetch_error — view the original via the link above.

OS impact

Debian Fixed 5 releases

Version	Status	Fixed in
trixie	Fixed	`1:1.10.9+submodules+notgz-1.1`
sid	Fixed	`1:1.10.9+submodules+notgz-1.1`
forky	Fixed	`1:1.10.9+submodules+notgz-1.1`
bullseye	Fixed	`1:1.10.9+submodules+notgz-1.1`
bookworm	Fixed	`1:1.10.9+submodules+notgz-1.1`

Red Hat Fixed 1 release

Version	Status	Fixed in
8	Fixed	—

Rocky Linux Fixed 1 release

Version	Status	Fixed in
8	Fixed	—

Package impact

Ecosystem	Package	Vulnerable	Fixed
Packagist	drupal/core	`>=8.0.0,<8.8.12\|\|>=8.9.0,<8.9.10\|\|>=9.0.0,<9.0.9`	`8.8.12`
Packagist	pear/archive_tar	`<1.4.11`	`1.4.11`

References

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.