PEAR Archive_Tar up to 1.4.3 $v_header[filename] Unserialize deserialization

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7.2$0-$5k0.00

A vulnerability classified as critical was found in PEAR Archive_Tar up to 1.4.3. Affected by this vulnerability is an unknown part. The manipulation of the argument $v_header[filename] as part of a Parameter leads to a deserialization vulnerability (Unserialize). The CWE definition for the vulnerability is CWE-502. The product deserializes untrusted data without sufficiently verifying that the resulting data will be valid. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

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 bug was discovered 01/10/2019. The weakness was disclosed 12/28/2018 (Website). It is possible to read the advisory at pear.php.net. This vulnerability is known as CVE-2018-1000888 since 12/27/2018. The attack can be launched remotely. The exploitation doesn't need any form of authentication. It demands that the victim is doing some kind of user interaction. Technical details and also a public exploit are known.

It is possible to download the exploit at exploit-db.com. It is declared as proof-of-concept. The vulnerability scanner Nessus provides a plugin with the ID 121187 (Ubuntu 16.04 LTS / 18.04 LTS / 18.10 : php-pear vulnerability (USN-3857-1)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Ubuntu Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 176687 (Debian Security Update for drupal7 (DLA 1685-1)).

Upgrading eliminates this vulnerability. A possible mitigation has been published 3 weeks after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (121187) and Exploit-DB (46108). The entries 129991 and 129992 are pretty similar.

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CPE 2.3info

CPE 2.2info

CVSSv4info

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CVSSv3info

VulDB Meta Base Score: 7.5
VulDB Meta Temp Score: 7.2

VulDB Base Score: 6.3
VulDB Temp Score: 5.7
VulDB Vector: 🔍
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NVD Base Score: 8.8
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CVSSv2info

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Exploitinginfo

Name: Unserialize
Class: Deserialization / Unserialize
CWE: CWE-502 / CWE-20
CAPEC: 🔍
ATT&CK: 🔍

Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Proof-of-Concept
Download: 🔍

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Nessus ID: 121187
Nessus Name: Ubuntu 16.04 LTS / 18.04 LTS / 18.10 : php-pear vulnerability (USN-3857-1)
Nessus File: 🔍
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Threat Intelligenceinfo

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Countermeasuresinfo

Recommended: Upgrade
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Timelineinfo

12/27/2018 🔍
12/28/2018 +1 days 🔍
12/28/2018 +0 days 🔍
12/29/2018 +1 days 🔍
01/10/2019 +12 days 🔍
01/14/2019 +4 days 🔍
01/15/2019 +1 days 🔍
01/16/2019 +1 days 🔍
06/22/2023 +1618 days 🔍

Sourcesinfo

Advisory: 23782
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2018-1000888 (🔍)
SecurityFocus: 106706 - Drupal CVE-2019-6338 PHP Object Injection Vulnerability

scip Labs: https://www.scip.ch/en/?labs.20161013
See also: 🔍

Entryinfo

Created: 12/29/2018 11:41
Updated: 06/22/2023 10:24
Changes: 12/29/2018 11:41 (75), 04/24/2020 16:49 (9), 06/22/2023 10:17 (4), 06/22/2023 10:24 (1)
Complete: 🔍
Cache ID: 18:1EF:103

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