CVE-2018-1000888: canonical ubuntu_linux Deserialization of Untrusted Data

Vulnerability summary

CVE-2018-1000888 is a high (CVSS 8.8) Deserialization of Untrusted Data vulnerability in canonical ubuntu_linux. EPSS estimates a 19.13% chance of exploitation in the next 30 days, higher than 97.3% of scored vulnerabilities. 3 public exploits are recorded.

Timeline

1. 27-12-2018
   PublishedVulnerability first disclosed.
2. 05-08-2024
   Last modifiedVulnerability information updated.

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.

• CWE-502Deserialization of Untrusted DataThe product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.