Vulnerability identifier: #VU23798

Vulnerability risk: High

CVSSv3.1: 7.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-19334

CWE-ID: CWE-121

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 attacker to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error when libyang parses YANG files with a leaf of type "identityref". A remote unauthenticated attacker can pass to the application an untrusted YANG file, trigger stack-based buffer overflow and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation
Install update from vendor's website.

Vulnerable software versions

libyang: 0.11-r1 - 1.0-r4

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External links
http://access.redhat.com/errata/RHSA-2019:4360
http://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-19334
http://github.com/CESNET/libyang/commit/6980afae2ff9fcd6d67508b0a3f694d75fd059d6
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PETB6TVMFV5KUD4IKVP2JPLBCYHUGSAJ/
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/RL54JMS7XW7PI6JC4BFSNNLSX5AINQUL/

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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.