Libgcrypt up to 1.7.6 Long-Term Session Key cipher/ecc-eddsa.c information disclosure

CVSS Meta Temp Score
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CTI Interest Score
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4.7$0-$5k0.00

Summaryinfo

A vulnerability classified as problematic has been found in Libgcrypt up to 1.7.6. This issue affects some unknown processing of the file cipher/ecc-eddsa.c of the component Long-Term Session Key. The manipulation leads to information disclosure. This vulnerability is uniquely identified as CVE-2017-9526. The attack is possible to be carried out remotely. No exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Libgcrypt up to 1.7.6 and classified as problematic. This issue affects some unknown processing of the file cipher/ecc-eddsa.c of the component Long-Term Session Key. 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. The summary by CVE is:

In Libgcrypt before 1.7.7, an attacker who learns the EdDSA session key (from side-channel observation during the signing process) can easily recover the long-term secret key. 1.7.7 makes a cipher/ecc-eddsa.c change to store this session key in secure memory, to ensure that constant-time point operations are used in the MPI library.

The bug was discovered 06/02/2017. The weakness was disclosed 06/11/2017 as Bug 1042326 as not defined bug report (Bugzilla). It is possible to read the advisory at bugzilla.suse.com. The identification of this vulnerability is CVE-2017-9526 since 06/10/2017. The exploitation is known to be difficult. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1592 according to MITRE ATT&CK.

The vulnerability was handled as a non-public zero-day exploit for at least 8 days. During that time the estimated underground price was around $0-$5k. The vulnerability scanner Nessus provides a plugin with the ID 100774 (Debian DSA-3880-1 : libgcrypt20 - security update), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Debian Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 196840 (Ubuntu Security Notification for Libgcrypt11, Libgcrypt20 Vulnerabilities (USN-3347-1)).

Upgrading to version 1.7.7 eliminates this vulnerability. A possible mitigation has been published 3 days after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (100774) and SecurityFocus (BID 99046†). The entries VDB-79791, VDB-95830, VDB-97118 and VDB-99028 are pretty similar. Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.8
VulDB Meta Temp Score: 4.7

VulDB Base Score: 3.7
VulDB Temp Score: 3.6
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 5.9
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: Information disclosure
CWE: CWE-200 / CWE-284 / CWE-266
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: 100774
Nessus Name: Debian DSA-3880-1 : libgcrypt20 - security update
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 703880
OpenVAS Name: Debian Security Advisory DSA 3880-1 (libgcrypt20 - 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: Libgcrypt 1.7.7
Patch: 5a22de904a0a366ae79f03ff1e13a1232a89e26b

Timelineinfo

06/01/2017 🔍
06/02/2017 +1 days 🔍
06/10/2017 +8 days 🔍
06/10/2017 +0 days 🔍
06/11/2017 +1 days 🔍
06/11/2017 +0 days 🔍
06/14/2017 +3 days 🔍
06/14/2017 +0 days 🔍
12/08/2022 +2003 days 🔍

Sourcesinfo

Advisory: Bug 1042326
Status: Not defined
Confirmation: 🔍

CVE: CVE-2017-9526 (🔍)
GCVE (CVE): GCVE-0-2017-9526
GCVE (VulDB): GCVE-100-102227

OVAL: 🔍

SecurityFocus: 99046 - Libgcrypt 'cipher/ecc-eddsa.c' Information Disclosure Vulnerability

See also: 🔍

Entryinfo

Created: 06/11/2017 11:54
Updated: 12/08/2022 11:15
Changes: 06/11/2017 11:54 (80), 10/16/2019 09:37 (5), 12/08/2022 11:15 (5)
Complete: 🔍
Cache ID: 216::103

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