CVE-2018-1000888
Archive_Tar contains Potential RCE if filename starts with phar://
Public exploit code
Working exploit or proof of concept code has been published for this vulnerability. Treat unpatched systems as at risk.
- PEAR Archive_Tar < 1.4.4 - PHP Object Injection2019-01-10 · webapps · php
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| composer | pear/archive_tar | < 1.4.4 | 1.4.4 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Php | Pear Archive Tar | through 1.4.3 |
| Canonical | Ubuntu Linux | Versions 16.04, 18.04, 18.10 |
| Debian | Debian Linux | Versions 8.0, 9.0 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://blog.ripstech.com/2018/new-php-exploitation-technique/
- https://cdn2.hubspot.net/hubfs/3853213/us-18-Thomas-It%27s-A-PHP-Unserialization-Vulnerability-Jim-But-Not-As-We-....pdf
- https://lists.debian.org/debian-lts-announce/2019/02/msg00020.html
- https://pear.php.net/bugs/bug.php?id=23782
- https://pear.php.net/package/Archive_Tar/download/
- https://security.gentoo.org/glsa/202006-14
- https://usn.ubuntu.com/3857-1/
- https://www.debian.org/security/2019/dsa-4378
- https://www.exploit-db.com/exploits/46108/
- https://github.com/advisories/GHSA-3q76-jq6m-573p
- 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://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