CVE-2018-1000888
Description
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.
Predictions
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 withsource_tier=community-verified.
Exploits
Public proof-of-concept code below. AS-IS, for defenders and authorised testing only.
Exploit-DB
PEAR Archive_Tar < 1.4.4 - PHP Object Injection
OS impact
Debian Fixed 5 releases
| Version | Status | Fixed in |
|---|---|---|
| trixie | Fixed | 1:1.10.6+submodules+notgz-1.1 |
| sid | Fixed | 1:1.10.6+submodules+notgz-1.1 |
| forky | Fixed | 1:1.10.6+submodules+notgz-1.1 |
| bullseye | Fixed | 1:1.10.6+submodules+notgz-1.1 |
| bookworm | Fixed | 1:1.10.6+submodules+notgz-1.1 |
Package impact
| Ecosystem | Package | Vulnerable | Fixed |
|---|---|---|---|
| Packagist | pear/archive_tar | <1.4.4 | 1.4.4 |
References
- https://nvd.nist.gov/vuln/detail/CVE-2018-1000888
- https://github.com/pear/Archive_Tar/commit/59ace120ac5ceb5f0d36e40e48e1884de1badf76
- https://github.com/FriendsOfPHP/security-advisories/blob/master/pear/archive_tar/CVE-2018-1000888.yaml
- https://github.com/pear/Archive_Tar
- https://lists.debian.org/debian-lts-announce/2019/02/msg00020.html
- https://pear.php.net/bugs/bug.php?id=23782
- https://security.gentoo.org/glsa/202006-14
- https://usn.ubuntu.com/3857-1
- https://web.archive.org/web/20210328115328/https://cdn2.hubspot.net/hubfs/3853213/us-18-Thomas-It's-A-PHP-Unserialization-Vulnerability-Jim-But-Not-As-We-....pdf
- https://web.archive.org/web/20220524160841/https://blog.sonarsource.com/new-php-exploitation-technique?redirect=rips
- https://www.debian.org/security/2019/dsa-4378
- https://www.exploit-db.com/exploits/46108
- https://security-tracker.debian.org/tracker/CVE-2018-1000888
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.