PHP up to 5.5.36/5.6.22/7.0.7 zip Extension php_zip.c use after free

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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A vulnerability classified as critical has been found in PHP up to 5.5.36/5.6.22/7.0.7 (Programming Language Software). This affects an unknown part of the file php_zip.c of the component zip Extension. The manipulation with an unknown input leads to a use after free vulnerability. CWE is classifying the issue as CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. This is going to have an impact on confidentiality, integrity, and availability.

The weakness was shared 08/07/2016 by Taoguang Chen (Website). It is possible to read the advisory at This vulnerability is uniquely identified as CVE-2016-5773 since 06/23/2016. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details and a public exploit are known.

It is declared as proof-of-concept. The exploit is shared for download at We expect the 0-day to have been worth approximately $25k-$100k. The vulnerability scanner Nessus provides a plugin with the ID 91839 (FreeBSD : php -- multiple vulnerabilities (66d77c58-3b1d-11e6-8e82-002590263bf5)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family FreeBSD Local Security Checks and running in the context local. The commercial vulnerability scanner Qualys is able to test this issue with plugin 175784 (Debian Security Update for php5 (DSA 3618-1)).

Upgrading to version 5.5.37, 5.6.23 or 7.0.8 eliminates this vulnerability. A possible mitigation has been published even before and not after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (91839) and Exploit-DB (40414). The entries 67631, 68572, 68959 and 77708 are related to this item.





  • open-source

CPE 2.3info

CPE 2.2info


VulDB Meta Base Score: 9.8
VulDB Meta Temp Score: 9.3

VulDB Base Score: 9.8
VulDB Temp Score: 8.8
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 9.8
NVD Vector: 🔍



VulDB Base Score: 🔍
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NVD Base Score: 🔍


Class: Use after free
CWE: CWE-416 / CWE-119
ATT&CK: Unknown

Local: No
Remote: Yes

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

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍


Nessus ID: 91839
Nessus Name: FreeBSD : php -- multiple vulnerabilities (66d77c58-3b1d-11e6-8e82-002590263bf5)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 14611
OpenVAS Name: Amazon Linux Local Check: alas-2016-728
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Exploit-DB: 🔍

Threat Intelligenceinfo

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


Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: PHP 5.5.37/5.6.23/7.0.8


06/23/2016 🔍
06/23/2016 +0 days 🔍
06/25/2016 +2 days 🔍
06/27/2016 +2 days 🔍
08/07/2016 +41 days 🔍
08/07/2016 +0 days 🔍
08/08/2016 +1 days 🔍
09/13/2022 +2227 days 🔍



Advisory: 72434
Researcher: Taoguang Chen
Status: Not defined
Confirmation: 🔍

CVE: CVE-2016-5773 (🔍)

SecurityFocus: 91397 - PHP 'ext/zip/php_zip.c' Use After Free Remote Code Execution Vulnerability

scip Labs:
See also: 🔍


Created: 08/08/2016 03:24 PM
Updated: 09/13/2022 09:44 AM
Changes: 08/08/2016 03:24 PM (57), 03/22/2019 08:55 AM (27), 09/13/2022 09:42 AM (4), 09/13/2022 09:44 AM (1)
Complete: 🔍


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