Ghostscript up to 9.20 SAFER Mode initialize_dsc_parser information disclosure

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	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 Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.8	$0-$5k	0.00

Summaryinfo

A vulnerability was found in Ghostscript up to 9.20. It has been classified as critical. Impacted is an unknown function in the library libfile of the file initialize_dsc_parser of the component SAFER Mode. The manipulation leads to information disclosure. This vulnerability is referenced as CVE-2016-7977. Remote exploitation of the attack is possible. No exploit is available. Applying a patch is the recommended action to fix this issue.

Detailsinfo

A vulnerability was found in Ghostscript up to 9.20 (Document Processing Software). It has been rated as critical. This issue affects an unknown code block in the library libfile of the file initialize_dsc_parser of the component SAFER Mode. The manipulation with an unknown input leads to a information disclosure vulnerability. Using CWE to declare the problem leads to CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. Impacted is 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 read arbitrary files via the use of the .libfile operator in a crafted postscript document.

The bug was discovered 10/05/2016. The weakness was published 05/23/2017 by Tavis Ormandy (oss-sec). The advisory is shared at openwall.com. The identification of this vulnerability is CVE-2016-7977 since 09/09/2016. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1592 for this issue.

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 95334†). Similar entries are available at VDB-76958, VDB-97580, VDB-99889 and VDB-101647. If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

• Document Processing Software

Name

• Ghostscript

Version

• 9.0
• 9.1
• 9.2
• 9.3
• 9.4
• 9.5
• 9.6
• 9.7
• 9.8
• 9.9
• 9.10
• 9.11
• 9.12
• 9.13
• 9.14
• 9.15
• 9.16
• 9.17
• 9.18
• 9.19
• 9.20

License

• free

CPE 2.3info

• 🔍
• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍
• 🔍

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.9
VulDB Meta Temp Score: 5.8

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

NVD Base Score: 5.5
NVD Vector: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
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Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

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

NVD Base Score: 🔍

Exploitinginfo

Class: Information disclosure
CWE: CWE-200 / CWE-284 / CWE-266
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

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: 8abd22010eb4db0fb1b10e430d5f5d83e015ef70

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-2016-7977 (🔍)
GCVE (CVE): GCVE-0-2016-7977
GCVE (VulDB): GCVE-100-101645

OVAL: 🔍

SecurityFocus: 95334 - Ghostscript CVE-2016-7977 Information Disclosure Vulnerability
OSVDB: - CVE-2016-7977 - Ghostscript - Security Bypass Issue

See also: 🔍

Entryinfo

Created: 05/23/2017 12:43
Updated: 12/07/2022 08:22
Changes: 05/23/2017 12:43 (79), 10/02/2020 09:20 (6), 12/07/2022 08:22 (5)
Complete: 🔍
Cache ID: 216:9E1:103

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