6.5

CVE-2019-20398: cesnet libyang NULL Pointer Dereference

CVSS: 6.5v3.1MediumModified
AliasesUBUNTU-CVE-2019-20398DEBIAN-CVE-2019-20398
Published 22-01-2020Last modified 05-08-2024
Open JSON

Vulnerability summary

CVE-2019-20398 is a medium (CVSS 6.5) NULL Pointer Dereference vulnerability in cesnet libyang. EPSS estimates a 1.82% chance of exploitation in the next 30 days, higher than 78.4% of scored vulnerabilities. 1 public exploit is recorded.

Overall risk
36/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.5/10
010
Medium · v3.1 (NVD)
EPSS score
1.82%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1github

Advisory lineage

Upstream 0 · Downstream 2
DLA-3572-1RHEA-2021:1906

Timeline

  1. 22-01-2020
    PublishedVulnerability first disclosed.
  2. 05-08-2024
    Last modifiedVulnerability information updated.

Description

A NULL pointer dereference is present 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.

CVSS metrics

4 scores · 3 sources · 2 versions

EPSS trend

Probability

1.82%

Chance of exploitation in the next 30 days

Percentile

78%

Versus all other CVEs

30-day change

0.00 pp

From 1.82% on 20-09-2026

20-09-202620-10-2026
EPSS score
1.82%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

1 found
  • githubUnverified

    Libyang

    Maturity: poc

Weaknesses

CWE · root cause

Affected systems

Cesnet1 product
  • libyang0.11:r1 | 0.11:r2 | 0.12:r1 | 0.12:r2 | 0.13:r1 | 0.13:r2 | 0.14:r1 | 0.15:r1 | 0.16:r1 | 0.16:r2 | 0.16:r3 | 1.0:r1 | 1.0:r2
Debian1 product
  • libyang< 1.0.176-1
Ubuntu1 product
  • libyangAll versions (No fix recorded)

3 vendors · 3 products

References

8 links