Ghostscript up to 9.20 SAFER Mode initialize_dsc_parser type conversion

CVSS Meta Temp Score
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CTI Interest Score
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7.9$0-$5k0.00

Summaryinfo

A vulnerability was found in Ghostscript up to 9.20. It has been rated as critical. The impacted element is an unknown function of the file initialize_dsc_parser of the component SAFER Mode. This manipulation causes type conversion. This vulnerability is tracked as CVE-2016-7979. The attack is possible to be carried out remotely. No exploit exists. It is recommended to apply a patch to fix this issue.

Detailsinfo

A vulnerability classified as critical was found in Ghostscript up to 9.20 (Document Processing Software). Affected by this vulnerability is an unknown function of the file initialize_dsc_parser of the component SAFER Mode. The manipulation with an unknown input leads to a type conversion vulnerability. The CWE definition for the vulnerability is CWE-704. The product does not correctly convert an object, resource, or structure from one type to a different type. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

Ghostscript before 9.21 might allow remote attackers to bypass the SAFER mode protection mechanism and consequently execute arbitrary code by leveraging type confusion in .initialize_dsc_parser.

The bug was discovered 10/05/2016. The weakness was disclosed 05/23/2017 by Tavis Ormandy (oss-sec). It is possible to read the advisory at openwall.com. This vulnerability is known as CVE-2016-7979 since 09/09/2016. 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 of the vulnerability are known, but there is no available exploit.

The vulnerability was handled as a non-public zero-day exploit for at least 97 days. During that time the estimated underground price was around $0-$5k. The vulnerability scanner Nessus provides a plugin with the ID 96395 (Amazon Linux AMI : ghostscript (ALAS-2017-784)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Amazon Linux Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 169242 (SUSE Enterprise Linux Security Update for ghostscript-library (SUSE-SU-2016:2493-1)).

Upgrading to version 9.21 eliminates this vulnerability. Applying a patch is able to eliminate this problem. The bugfix is ready for download at git.ghostscript.com. The best possible mitigation is suggested to be patching the affected component. A possible mitigation has been published before and not just after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (96395) and SecurityFocus (BID 95337†). The entries VDB-76958, VDB-99889, VDB-101645 and VDB-101646 are pretty similar. Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.0
VulDB Meta Temp Score: 7.9

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 9.8
NVD Vector: 🔍

CVSSv2info

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

NVD Base Score: 🔍

Exploitinginfo

Class: Type conversion
CWE: CWE-704
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: 96395
Nessus Name: Amazon Linux AMI : ghostscript (ALAS-2017-784)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 703691
OpenVAS Name: Debian Security Advisory DSA 3691-1 (ghostscript - security update)
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔍

Upgrade: Ghostscript 9.21
Patch: 875a0095f37626a721c7ff57d606a0f95af03913

Timelineinfo

09/09/2016 🔍
10/05/2016 +26 days 🔍
10/05/2016 +0 days 🔍
01/10/2017 +97 days 🔍
01/11/2017 +1 days 🔍
05/23/2017 +132 days 🔍
05/23/2017 +0 days 🔍
05/23/2017 +0 days 🔍
12/07/2022 +2024 days 🔍

Sourcesinfo

Advisory: RHSA-2017:0013
Researcher: Tavis Ormandy
Status: Not defined
Confirmation: 🔍

CVE: CVE-2016-7979 (🔍)
GCVE (CVE): GCVE-0-2016-7979
GCVE (VulDB): GCVE-100-101647

OVAL: 🔍

SecurityFocus: 95337 - Ghostscript CVE-2016-7979 Remote Code Execution Vulnerability
OSVDB: - CVE-2016-7979 - Ghostscript - Type Confusion Issue

See also: 🔍

Entryinfo

Created: 05/23/2017 12:44
Updated: 12/07/2022 08:29
Changes: 05/23/2017 12:44 (78), 10/02/2020 09:23 (6), 12/07/2022 08:29 (5)
Complete: 🔍
Cache ID: 216:0E8:103

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