Vulnerability 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.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Php | Pear Archive Tar | <= 1.4.3 |
| Canonical | Ubuntu Linux | 16.04 |
| Debian | Debian Linux | 8.0 |
Related Weaknesses (CWE)
References
- https://blog.ripstech.com/2018/new-php-exploitation-technique/ExploitThird Party Advisory
- https://cdn2.hubspot.net/hubfs/3853213/us-18-Thomas-It%27s-A-PHP-UnserializationExploitTechnical DescriptionThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2019/02/msg00020.htmlThird Party Advisory
- https://pear.php.net/bugs/bug.php?id=23782Broken LinkThird Party Advisory
- https://pear.php.net/package/Archive_Tar/download/Broken LinkThird Party Advisory
- https://security.gentoo.org/glsa/202006-14
- https://usn.ubuntu.com/3857-1/Third Party Advisory
- https://www.debian.org/security/2019/dsa-4378Third Party Advisory
- https://www.exploit-db.com/exploits/46108/ExploitThird Party AdvisoryVDB Entry
- https://blog.ripstech.com/2018/new-php-exploitation-technique/ExploitThird Party Advisory
- https://cdn2.hubspot.net/hubfs/3853213/us-18-Thomas-It%27s-A-PHP-UnserializationExploitTechnical DescriptionThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2019/02/msg00020.htmlThird Party Advisory
- https://pear.php.net/bugs/bug.php?id=23782Broken LinkThird Party Advisory
- https://pear.php.net/package/Archive_Tar/download/Broken LinkThird Party Advisory
- https://security.gentoo.org/glsa/202006-14
FAQ
What is CVE-2018-1000888?
CVE-2018-1000888 is a vulnerability with a CVSS score of 8.8 (HIGH). 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...
How severe is CVE-2018-1000888?
CVE-2018-1000888 has been rated HIGH with a CVSS base score of 8.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2018-1000888?
Check the references section above for vendor advisories and patch information. Affected products include: Php Pear Archive Tar, Canonical Ubuntu Linux, Debian Debian Linux.