Skip to content
Fencer Intel
high 8.8

CVE-2018-1000888 in the critical feed json

Archive_Tar contains Potential RCE if filename starts with phar://

published 7y ago modified 4mo ago also GHSA-3q76-jq6m-573p , EUVD-2023-1941

cvss
8.8
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
19.1%
EPSS 19.1% chance of exploitation in 30 days, percentile 97%
public exploits
1
Exploit-DB

Summary

PEAR Archive_Tar version 1.4.3 and earlier contains a CWE-502, CWE-915 vulnerability in the Archive_Tar class. There are several file operations with `$v_header['filename']` as parameter (such as file_exists, is_file, is_dir, etc). When extract is called without a specific prefix path, we can trigger unserialization by crafting a tar file with `phar://[path_to_malicious_phar_file]` as path. Object injection can be used to trigger destruct in the loaded PHP classes, e.g. the Archive_Tar class itself. With Archive_Tar object injection, arbitrary file deletion can occur because `@unlink($this->_temp_tarname)` is called. If another class with useful gadget is loaded, it may possible to cause remote code execution that can result in files being deleted or possibly modified. This vulnerability appears to have been fixed in 1.4.4.

Patch / fix

  • packagist pear/archive_tar 1.4.4
  • php-pear Debian 14, Debian 13, Debian 12 1:1.10.6+submodules+notgz-1.1

debian advisories DEBIAN-CVE-2018-1000888

  • php-pear Ubuntu 16.04 LTS 1:1.10.1+submodules+notgz-6ubuntu0.1
  • php-pear Ubuntu 18.04 LTS 1:1.10.5+submodules+notgz-1ubuntu1.18.04.1

ubuntu advisories UBUNTU-CVE-2018-1000888

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • php7 openSUSE Tumbleweed 7.4.24-1.1
  • php8 openSUSE Tumbleweed 8.0.11-1.1

opensuse advisories openSUSE-SU-2024:11167-1openSUSE-SU-2024:11169-1

  • drupal7 Alpine 3.20, Alpine 3.19, Alpine 3.18 +10 more 7.62-r0

alpine advisories ALPINE-CVE-2018-1000888

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Is CVE-2018-1000888 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2018-1000888 updated cvss 8.1

php-pear: Unsafe deserialization of data in Archive_Tar class

  • Red Hat Enterprise Linux 6 php-pear Red Hat Enterprise Linux 7 php-pear Red Hat Enterprise Linux 8 php-pear
    affected: no fix planned “Will not fix”
  • Red Hat Software Collections rh-php70-php-pear, rh-php71-php-pear, rh-php72-php-pear, rh-php73-php-pear
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 5 php-pear
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Timeline

  1. Published
  2. First public exploit (EDB-46108)

Exploit prediction

19.13% chance of exploitation in the next 30 days, higher than 97% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • EDB-46108 PEAR Archive_Tar < 1.4.4 - PHP Object Injection webapps, 2019-01-10
  • cdn2.hubspot.net https://cdn2.hubspot.net/hubfs/3853213/us-18-Thomas-It%27s-A-PHP-Unserialization-Vulnerability-Jim-But-Not-As-We-....pdf referenced PoC, tagged "exploit" by a source, unverified
  • blog.ripstech.com https://blog.ripstech.com/2018/new-php-exploitation-technique/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.0 8.8 CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD 2.0 6.8 AV:N/AC:M/Au:N/C:P/I:P/A:P
GitHub 3.0 8.8 CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
packagist pear/archive_tar
<1.4.4
1.4.4

Classification

Weakness
  • CWE-502 Deserialization of Untrusted Data

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.