Vulnerability identifier: #VU34862

Vulnerability risk: Medium

CVSSv3.1: 5.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-20392

CWE-ID: CWE-119

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
libyang
Universal components / Libraries / Libraries used by multiple products

Vendor: CESNET

Description

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-r1 in the function resolve_feature_value() when an if-feature statement is used inside a list key node, and the feature used is not defined. Applications that use libyang to parse untrusted input yang files may crash.

Mitigation
Install update from vendor's website.

Vulnerable software versions

libyang: 0.11 - 0.16

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External links
http://bugzilla.redhat.com/show_bug.cgi?id=1793922
http://github.com/CESNET/libyang/commit/32fb4993bc8bb49e93e84016af3c10ea53964be5
http://github.com/CESNET/libyang/compare/v0.16-r3...v1.0-r1
http://github.com/CESNET/libyang/issues/723

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.