PHP up to 7.3.30/7.4.23/8.0.10 on Windows ZipArchive::extractTo path traversal

CVSS Meta Temp Score
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Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
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A vulnerability was found in PHP up to 7.3.30/7.4.23/8.0.10 on Windows (Programming Language Software). It has been declared as critical. This vulnerability affects the function ZipArchive::extractTo. The manipulation with an unknown input leads to a path traversal vulnerability. The CWE definition for the vulnerability is CWE-23. The software uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize sequences such as ".." that can resolve to a location that is outside of that directory. As an impact it is known to affect integrity, and availability.

The weakness was disclosed 10/04/2021 as 81420. The advisory is available at This vulnerability was named CVE-2021-21706 since 01/04/2021. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 10/04/2021). This vulnerability is assigned to T1006 by the MITRE ATT&CK project.

Upgrading to version 7.3.31, 7.4.24 or 8.0.11 eliminates this vulnerability.





  • open-source

CPE 2.3info

CPE 2.2info


VulDB Meta Base Score: 5.0
VulDB Meta Temp Score: 4.9

VulDB Base Score: 4.8
VulDB Temp Score: 4.6
VulDB Vector: 🔍
VulDB Reliability: 🔍

CNA Base Score: 5.3
CNA Vector (PHP Group): 🔍



VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍


Class: Path traversal
CWE: CWE-23 / CWE-22
ATT&CK: T1006

Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍


Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍


Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: PHP 7.3.31/7.4.24/8.0.11


01/04/2021 🔍
10/04/2021 +272 days 🔍
10/04/2021 +0 days 🔍
10/08/2021 +4 days 🔍



Advisory: 81420
Status: Confirmed

CVE: CVE-2021-21706 (🔍)


Created: 10/04/2021 07:46 AM
Updated: 10/08/2021 02:22 PM
Changes: 10/04/2021 07:46 AM (51), 10/08/2021 02:22 PM (1)
Complete: 🔍


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