CVE-2020-28949: Pear/archive tar Multiple Vulnerabilities Through Filename Manipulation Vulnerability

HIGH
Advisory Identifier: GHSA-75c5-f4gw-38r9
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CVSS 7.8
CWE-74
Published
Advisory Summary

CVE-2020-28949 is a HIGH (CVSS 7.8) multiple vulnerabilities through filename manipulation vulnerability (CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')) affecting Pear/archive tar libraries in the Packagist ecosystem. The issue involves multiple vulnerabilities through filename manipulation in archive_tar. Remediation is available by upgrading affected packages to version 1.4.11.

CVE-2020-28949 at a Glance

CVE Identifier CVE-2020-28949
GHSA Identifier GHSA-75c5-f4gw-38r9
Severity HIGH
CVSS v3.1 Base Score 7.8
CWE Classification CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
Affected Product Pear/archive tar
Package Ecosystem Packagist
Published Date
Last Updated

Security Impact

CVSS: 7.8

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:H).

Attack Vector Local (AV:L)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction Required (UI:R)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2020-28949

To remediate this vulnerability, upgrade all affected Pear/archive tar dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

pear/archive_tar fixed: 1.4.11 
Upgrade pear/archive_tar to 1.4.11
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for pear/archive_tar

How to Check if You Are Affected

To determine whether your application is affected by CVE-2020-28949, inspect your project dependencies for Pear/archive tar:

inspect dependencies for pear/archive_tar

Analyze the terminal output to locate any version of Pear/archive tar in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.4.11), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection'), where the product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component. In Pear/archive tar, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

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

CVE-2020-28949 Affected Pear/archive tar Versions

1 component(s)
Fixed Versions:
1.4.11
Product / Package Ecosystem Affected Versions Fixed Version
pear/archive_tar
 Packagist
< 1.4.11
1.4.11

References

NVD — CVE-2020-28949 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-28949
Pear/archive tar Source Repository REPOSITORY
https://github.com/pear/Archive_Tar/issues/33
Security Fix Commit FIX COMMIT
https://github.com/pear/Archive_Tar/commit/0670a05fdab997036a3fc3ef113b8f5922e574da
www.drupal.org/sa-core-2020-013 WEB
https://www.drupal.org/sa-core-2020-013
Pear/archive tar Security Information SECURITY
https://www.debian.org/security/2020/dsa-4817
www.cisa.gov/known-exploited-vul... WEB
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-28949
Pear/archive tar Security Information SECURITY
https://security.gentoo.org/glsa/202101-23
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/VJQQYDAOWHD6RDITDRPHFW7WY6BS3V5N
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/NBYZSHYTIOBK6V7C4N7TP6KIKCRKLVWP
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/KWM4CTMEGAC4I2CHYNJVSROY4CVXVEUT
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/5KSFM672XW3X6BR7TVKRD63SLZGKK437
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/4V35LBRM6HBCXBVCITKQ4UEBTXO2EG7B
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/42GPGVVFTLJYAKRI75IVB5R45NYQGEUR
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VJQQYDAOWHD6RDITDRPHFW7WY6BS3V5N
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NBYZSHYTIOBK6V7C4N7TP6KIKCRKLVWP
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KWM4CTMEGAC4I2CHYNJVSROY4CVXVEUT
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5KSFM672XW3X6BR7TVKRD63SLZGKK437
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4V35LBRM6HBCXBVCITKQ4UEBTXO2EG7B
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/42GPGVVFTLJYAKRI75IVB5R45NYQGEUR
lists.debian.org/debian-lts-announce... WEB
https://lists.debian.org/debian-lts-announce/2020/11/msg00045.html
Pear/archive tar Source Repository REPOSITORY
https://github.com/pear/Archive_Tar
Pear/archive tar Source Repository REPOSITORY
https://github.com/FriendsOfPHP/security-advisories/blob/master/pear/archive_tar/CVE-2020-28949.yaml
Pear/archive tar Security Information SECURITY
http://packetstormsecurity.com/files/161095/PEAR-Archive_Tar-Arbitrary-File-Write.html

Frequently Asked Questions

What is CVE-2020-28949?
CVE-2020-28949 is a security vulnerability in Pear/archive tar involving Multiple vulnerabilities through filename manipulation in Archive_Tar under CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection').
Which Pear/archive tar versions are affected?
Affected versions include releases prior to 1.4.11 across affected packages: pear/archive_tar.
What version fixes CVE-2020-28949?
Upgrading to 1.4.11 (or the latest patched release for your respective branch) resolves the vulnerability.
Is pear/archive_tar affected?
Yes, pear/archive_tar is affected in releases prior to 1.4.11. Upgrade your dependency to 1.4.11 or later.
What is the CVSS score of CVE-2020-28949?
CVE-2020-28949 has a CVSS v3.1 base score of 7.8 (HIGH) with vector string CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:H.
What CWE is associated with CVE-2020-28949?
CVE-2020-28949 is classified under CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection') (The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.).
How can I check Packagist dependencies for CVE-2020-28949?
Run the dependency tree command: 'inspect dependencies for pear/archive_tar'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-75c5-f4gw-38r9",
  "modified" : "2025-10-22T17:56:52Z",
  "published" : "2021-04-22T16:20:59Z",
  "aliases" : [ "CVE-2020-28949" ],
  "summary" : "Multiple vulnerabilities through filename manipulation in Archive_Tar",
  "details" : "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",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "pear/archive_tar"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.4.11"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-28949"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pear/Archive_Tar/issues/33"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pear/Archive_Tar/commit/0670a05fdab997036a3fc3ef113b8f5922e574da"
  }, {
    "type" : "WEB",
    "url" : "https://www.drupal.org/sa-core-2020-013"
  }, {
    "type" : "WEB",
    "url" : "https://www.debian.org/security/2020/dsa-4817"
  }, {
    "type" : "WEB",
    "url" : "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-28949"
  }, {
    "type" : "WEB",
    "url" : "https://security.gentoo.org/glsa/202101-23"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/VJQQYDAOWHD6RDITDRPHFW7WY6BS3V5N"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/NBYZSHYTIOBK6V7C4N7TP6KIKCRKLVWP"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/KWM4CTMEGAC4I2CHYNJVSROY4CVXVEUT"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/5KSFM672XW3X6BR7TVKRD63SLZGKK437"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/4V35LBRM6HBCXBVCITKQ4UEBTXO2EG7B"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/42GPGVVFTLJYAKRI75IVB5R45NYQGEUR"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VJQQYDAOWHD6RDITDRPHFW7WY6BS3V5N"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NBYZSHYTIOBK6V7C4N7TP6KIKCRKLVWP"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KWM4CTMEGAC4I2CHYNJVSROY4CVXVEUT"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5KSFM672XW3X6BR7TVKRD63SLZGKK437"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4V35LBRM6HBCXBVCITKQ4UEBTXO2EG7B"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/42GPGVVFTLJYAKRI75IVB5R45NYQGEUR"
  }, {
    "type" : "WEB",
    "url" : "https://lists.debian.org/debian-lts-announce/2020/11/msg00045.html"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/pear/Archive_Tar"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/FriendsOfPHP/security-advisories/blob/master/pear/archive_tar/CVE-2020-28949.yaml"
  }, {
    "type" : "WEB",
    "url" : "http://packetstormsecurity.com/files/161095/PEAR-Archive_Tar-Arbitrary-File-Write.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-74" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-03-23T00:20:31Z",
    "nvd_published_at" : "2020-11-19T19:15:00Z"
  }
}