How severe is CVE-2020-28948?

CVE-2020-28948 has a CVSS score of 7.8/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2020-28948?

CVE-2020-28948 affects the following packages: pear/archive_tar (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2020-28948?

Update pear/archive_tar to 1.4.11 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-28948 is resolved across your whole dependency graph.

How do I detect CVE-2020-28948 in my Packagist dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pear/archive_tar, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2020-28948 if there is no patch (or I can't update yet)?

Do not deserialise data from untrusted sources: where the format allows it, restrict deserialisation to an explicit allowlist of expected types, and prefer a data-only format (JSON, Protobuf) over one that can reconstruct arbitrary objects until you can upgrade.

Is CVE-2020-28948 actively exploited in the wild?

Yes. There are 5 known exploit references for CVE-2020-28948, including 3 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2020-28948?

CVE-2020-28948 has an EPSS (Exploit Prediction Scoring System) score of 47.5%, placing it in the 99th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score warrants monitoring and prompt remediation.

What type of vulnerability is CVE-2020-28948?

CVE-2020-28948 is classified as Deserialization of Untrusted Data (CWE-502). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2020-28948 published, and has it been updated?

CVE-2020-28948 was published on November 19, 2020 and was last updated on October 24, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐘

🐘 Packagist

Not in CISA KEV

HIGH severity

CVE-2020-28948 — archive_tar

HIGHFix: pear/Archive_Tar@0670a05

CVE-2020-28948 is a high-severity (CVSS 7.8) Deserialization of Untrusted Data vulnerability in pear/archive_tar. 5 public exploit or proof-of-concept references are indexed, so weaponization risk is real. A fix is available for pear/archive_tar — see the affected versions and patch details below.

Multiple vulnerabilities through filename manipulation in Archive_Tar

Also known asBIT-drupal-2020-28948BIT-drupal-2020-28949CVE-2020-28949DRUPAL-CORE-2020-013GHSA-75c5-f4gw-38r9 GHSA-jh5x-hfhg-78jq

Published

Nov 19, 2020

Updated

Oct 24, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

5 known

Exploitation data as of Nov 5, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

47.5%probability of exploitation in next 30 days

High Risk0.00%

Lower risk than most CVEs99th percentile — riskier than 99% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected

🐘pear/archive_tar

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.

Description

Archive_Tar through 1.4.10 has :// filename sanitization only to address phar attacks, and thus any other stream-wrapper attack (such as file:// to overwrite files) can still succeed. See: https://github.com/pear/Archive_Tar/issues/33

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`pear/archive_tar`	all versions	1.4.11`composer require pear/archive_tar:^1.4.11`

Affected Products

4 products · 11 configurations

debian linuxdebian

2 versions

9.010.0

Application

drupaldrupal

≥ 9.0.0 && < 9.0.9

range

fedorafedoraproject

4 versions

32333435

Application

archive tarphp

< 1.4.11

range

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

Archive_Tar through 1.4.10 allows an unserialization attack because phar…

github.comNVDFeb 2021

Report on github.com

github.comAwesomePocJun 2020

Report on github.com

github.comGithubNov 2020

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pear/archive_tar, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update pear/archive_tar to 1.4.11 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-28948 is resolved across your whole dependency graph.
Workarounds
Do not deserialise data from untrusted sources: where the format allows it, restrict deserialisation to an explicit allowlist of expected types, and prefer a data-only format (JSON, Protobuf) over one that can reconstruct arbitrary objects until you can upgrade.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate

PHP 7.2 and 7.3 marked End of Life at the time this CVE was released. There would be no patches made available for php-pear.

Product	Fixed in	Advisory
Red Hat Enterprise Linux 7	`php-pear-1:1.9.4-23.el7_9`	RHSA-2022:7340
Red Hat Enterprise Linux 8	`php:7.4-8060020220907094815.5caa48ff`	RHSA-2022:6542
Red Hat Enterprise Linux 8.4 Extended Update Support	`php:7.4-8040020220907095003.d7c09045`	RHSA-2022:6541

Frequently Asked Questions

Archive_Tar through 1.4.10 has `://` filename sanitization only to address phar attacks, and thus any other stream-wrapper attack (such as `file://` to overwrite files) can still succeed. See: https://github.com/pear/Archive_Tar/issues/33

O3 Security · Impact-Aware SCA

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