Ghostscript up to 9.20 SAFER Mode initialize_dsc_parser information disclosure

CVSS Meta Temp Score
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CTI Interest Score
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5.8$0-$5k0.00

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 vulnerability database at Tenable (96395). Similar entries are available at 76958, 97580, 99889 and 101647.

Productinfo

Type

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB CVSS-B Score: 🔍
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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

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VulDB Base Score: 🔍
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Exploitinginfo

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

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: 🔍
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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 (🔍)
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: 🔍

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