CVE-2019-20392Public exploitNetwork attack vector

Application crash via premature feature evaluation

Published Jan 22, 2020 · Updated Aug 5, 2024

Invalid memory access in CESNET libyang before 1.0-r1 allows remote attackers to crash a parsing application with a crafted YANG file. resolve_feature_value evaluates feature state before schema resolution finishes, so an undefined if-feature on a list key triggers invalid memory access. Exploitation requires an application to parse attacker-supplied schema, and the demonstrated consequence is process termination rather than code execution.

CVSS severity6.5
Medium
EPSS probability1.86%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Invalid memory access in CESNET libyang before 1.0-r1 allows remote attackers to crash a parsing application with a crafted YANG file. resolve_feature_value evaluates feature state before schema resolution finishes, so an undefined if-feature on a list key triggers invalid memory access. Exploitation requires an application to parse attacker-supplied schema, and the demonstrated consequence is process termination rather than code execution.

The record

CVE
CVE-2019-20392
Published
Jan 22, 2020
Updated
Aug 5, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-119, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 22, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:N/A:P
6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-119Improper Restriction of Operations within the Bounds of a Memory Buffer
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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