PHP up to 7.0.20/7.1.6 var_unserializer.re zval_get_type use after free

CVSS Meta Temp Score
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CTI Interest Score
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7.2$0-$5k0.00

Summaryinfo

A vulnerability described as critical has been identified in PHP up to 7.0.20/7.1.6. This affects the function zval_get_type of the file ext/standard/var_unserializer.re. The manipulation results in use after free. This vulnerability is reported as CVE-2017-12934. The attack can be launched remotely. No exploit exists. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in PHP up to 7.0.20/7.1.6 (Programming Language Software). It has been classified as critical. Affected is the function zval_get_type of the file ext/standard/var_unserializer.re. 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. CVE summarizes:

ext/standard/var_unserializer.re in PHP 7.0.x before 7.0.21 and 7.1.x before 7.1.7 is prone to a heap use after free while unserializing untrusted data, related to the zval_get_type function in Zend/zend_types.h. Exploitation of this issue can have an unspecified impact on the integrity of PHP.

The bug was discovered 08/14/2017. The weakness was disclosed 08/18/2017 (Website). The advisory is shared for download at php.net. This vulnerability is traded as CVE-2017-12934 since 08/17/2017. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available.

The vulnerability was handled as a non-public zero-day exploit for at least 3 days. During that time the estimated underground price was around $5k-$25k. The vulnerability scanner Nessus provides a plugin with the ID 103286 (openSUSE Security Update : php7 (openSUSE-2017-1061)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family SuSE Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 170344 (SUSE Enterprise Linux Security Update for php7 (SUSE-SU-2017:2468-1)).

Upgrading to version 7.0.21 or 7.1.7 eliminates this vulnerability. A possible mitigation has been published 4 weeks after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (103286) and SecurityFocus (BID 100428†). The entries VDB-80326, VDB-80327, VDB-83183 and VDB-83184 are pretty similar. VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

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Version

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Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.4
VulDB Meta Temp Score: 7.2

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.5
NVD Vector: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

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

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 103286
Nessus Name: openSUSE Security Update : php7 (openSUSE-2017-1061)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 863753
OpenVAS Name: Debian Security Advisory DSA 4080-1 (php7.0 - security update)
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍

Upgrade: PHP 7.0.21/7.1.7

Timelineinfo

08/14/2017 🔍
08/17/2017 +3 days 🔍
08/17/2017 +0 days 🔍
08/17/2017 +0 days 🔍
08/18/2017 +1 days 🔍
08/18/2017 +0 days 🔍
09/15/2017 +28 days 🔍
09/18/2017 +3 days 🔍
12/16/2022 +1915 days 🔍

Sourcesinfo

Product: php.org

Advisory: RHSA-2018:1296
Researcher: cyoung
Status: Not defined
Confirmation: 🔍

CVE: CVE-2017-12934 (🔍)
GCVE (CVE): GCVE-0-2017-12934
GCVE (VulDB): GCVE-100-105432

OVAL: 🔍

SecurityFocus: 100428 - PHP CVE-2017-12934 Heap Based Buffer Overflow Vulnerability

See also: 🔍

Entryinfo

Created: 08/18/2017 12:34
Updated: 12/16/2022 08:07
Changes: 08/18/2017 12:34 (79), 11/08/2019 08:08 (5), 01/09/2021 16:51 (2), 12/16/2022 08:07 (3)
Complete: 🔍
Cache ID: 216::103

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