NULL pointer dereference in libyang - CVE-2019-20398
Published: January 22, 2020 / Updated: October 8, 2021
Vulnerability identifier: #VU34868
CSH Severity: Medium
CVSS v4: 6.9 [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]
CVE-ID: CVE-2019-20398
CWE-ID: CWE-476
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
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.
Affected software
libyang
Dell EMC PowerProtect Data Protection
SmartFabric OS10
Red Hat Enterprise Linux for x86_64
libyang (Red Hat package)
Dell EMC PowerProtect Data Protection
SmartFabric OS10
Red Hat Enterprise Linux for x86_64
libyang (Red Hat package)
How to mitigate CVE-2019-20398
Install update from vendor's website.
Dell EMC PowerProtect Data Protection - update to 2.7.8
SmartFabric OS10 - addressed in versions 10.5.5.9, 10.5.6.1
libyang (Red Hat package) - update to 1.0.184-1.el8
SmartFabric OS10 - addressed in versions 10.5.5.9, 10.5.6.1
libyang (Red Hat package) - update to 1.0.184-1.el8