Vulnerability CVE-2018-1000888


Published: 2018-12-28

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.

See advisories in our WLB2 database:
Topic
Author
Date
High
PEAR Archive_Tar PHP Object Injection
farisv
11.01.2019

Type:

CWE-502

(Deserialization of Untrusted Data)

CVSS2 => (AV:N/AC:M/Au:N/C:P/I:P/A:P)

CVSS Base Score
Impact Subscore
Exploitability Subscore
6.8/10
6.4/10
8.6/10
Exploit range
Attack complexity
Authentication
Remote
Medium
No required
Confidentiality impact
Integrity impact
Availability impact
Partial
Partial
Partial
Affected software
PHP -> Pear archive tar 
Debian -> Debian linux 
Canonical -> Ubuntu linux 

 References:
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://usn.ubuntu.com/3857-1/
https://www.debian.org/security/2019/dsa-4378
https://www.exploit-db.com/exploits/46108/

Copyright 2022, cxsecurity.com

 

Back to Top