CVE-2018-1000888

high-risk
Published 2018-12-28

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.

Do I need to act?

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29.5% chance of exploitation in next 30 days
EPSS score — higher than 71% of all CVEs
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Not on CISA KEV list
No confirmed active exploitation reported to CISA
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1 public exploit available
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Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
8
CVSS 8.8/10 High
NETWORK / LOW complexity

Affected Vendors

58
/ 100
high-risk
Severity 30/34 · Critical
Exploitability 15/34 · Moderate
Exposure 13/34 · Low