SB2020012248 - Multiple vulnerabilities in CESNET libyang



SB2020012248 - Multiple vulnerabilities in CESNET libyang

Published: January 22, 2020 Updated: October 8, 2021

Security Bulletin ID SB2020012248
CSH Severity
High
Patch available
YES
Number of vulnerabilities 3
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

High 33% Medium 67%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 3 vulnerabilities.


1) Buffer overflow (CVE-ID: CVE-2019-20391)

CWE-ID: CWE-119 - Memory corruption

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote non-authenticated attacker to perform a denial of service (DoS) attack.

An invalid memory access flaw is present in libyang before v1.0-r3 in the function resolve_feature_value() when an if-feature statement is used inside a bit. Applications that use libyang to parse untrusted input yang files may crash.


2) Double Free (CVE-ID: CVE-2019-20394)

CWE-ID: CWE-415 - Double Free

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber


The vulnerability allows a remote non-authenticated attacker to execute arbitrary code.

A double-free is present in libyang before v1.0-r3 in the function yyparse() when a type statement in used in a notification statement. Applications that use libyang to parse untrusted input yang files may be vulnerable to this flaw, which would cause a crash or potentially code execution.


3) NULL pointer dereference (CVE-ID: CVE-2019-20398)

CWE-ID: CWE-476 - NULL Pointer Dereference

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a NULL pointer dereference error in libyang before v1.0-r3 in the function lys_extension_instances_free() due to a copy of unresolved extensions in lys_restr_dup(). Applications that use libyang to parse untrusted input yang files may crash. A remote attacker can perform a denial of service (DoS) attack.


Remediation

Install update from vendor's website.