VDB-149253 · CVE-2019-20396 · Nessus 257937

libyang prior 1.0-r1 lys_parse_path Pattern input validation

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.
5.3	$0-$5k	0.00

Summaryinfo

A vulnerability classified as problematic has been found in libyang. Impacted is the function lys_parse_path. Performing a manipulation as part of Pattern results in input validation. This vulnerability was named CVE-2019-20396. The attack may be initiated remotely. There is no available exploit. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in libyang. It has been classified as problematic. This affects the function lys_parse_path. The manipulation as part of a Pattern leads to a input validation vulnerability. CWE is classifying the issue as CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. This is going to have an impact on availability. The summary by CVE is:

A segmentation fault is present in yyparse in libyang before v1.0-r1 due to a malformed pattern statement value during lys_parse_path parsing.

The weakness was presented 01/22/2020. This vulnerability is uniquely identified as CVE-2019-20396 since 01/22/2020. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 257937 (Linux Distros Unpatched Vulnerability : CVE-2019-20396), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 1.0-r1 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (257937). See VDB-149255, VDB-149254, VDB-149252 and VDB-149251 for similar entries. If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Name

libyang

License

open-source

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.4
VulDB Meta Temp Score: 5.3

VulDB Base Score: 4.3
VulDB Temp Score: 4.1
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 6.5
NVD Vector: 🔍

CVSSv2info

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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Input validation
CWE: CWE-20
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	Unlock	Unlock	Unlock	Unlock
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Nessus ID: 257937
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2019-20396

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: libyang 1.0-r1
Patch: github.com

Timelineinfo

01/22/2020 🔍
01/22/2020 +0 days 🔍
01/23/2020 +1 days 🔍
08/30/2025 +2046 days 🔍

Sourcesinfo

Advisory: a1f17693904ed6fecc8902c747fc50a8f20e6af8
Status: Confirmed

CVE: CVE-2019-20396 (🔍)
GCVE (CVE): GCVE-0-2019-20396
GCVE (VulDB): GCVE-100-149253
See also: 🔍

Entryinfo

Created: 01/23/2020 08:38
Updated: 08/30/2025 09:41
Changes: 01/23/2020 08:38 (37), 01/23/2020 08:43 (17), 03/25/2024 11:55 (20), 03/25/2024 12:02 (1), 08/30/2025 09:41 (5)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.