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.
The MITRE CVE dictionary describes this issue as:
Find out more about CVE-2018-1000888 from the MITRE CVE dictionary dictionary and NIST NVD.
NOTE: The following CVSS v3 metrics and score provided are preliminary and subject to review.
| CVSS3 Base Score | 7.4 |
|---|---|
| CVSS3 Base Metrics | CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H |
| Attack Vector | Network |
| Attack Complexity | High |
| Privileges Required | None |
| User Interaction | None |
| Scope | Unchanged |
| Confidentiality | None |
| Integrity Impact | High |
| Availability Impact | High |
| Platform | Package | State |
|---|---|---|
| Red Hat Enterprise Linux 7 | php-pear | Under investigation |
| Red Hat Enterprise Linux 6 | php-pear | Under investigation |
| Red Hat Enterprise Linux 5 | php-pear | Under investigation |
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