Skip to content
Fencer Vulns
medium 6.5

CVE-2020-19860 json

When ldns version 1.7.1 verifies a zone file, the ldns_rr_new_frm_str_internal function has a heap out of bounds read vulnerability.

published 2022-01-21 4 y ago modified 2026-06-17 4 mo ago also EUVD-2020-11756

cvss
6.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.2%
EPSS 1.2% chance of exploitation in 30 days, percentile 68%
public exploits
0
none known

Summary

When ldns version 1.7.1 verifies a zone file, the ldns_rr_new_frm_str_internal function has a heap out of bounds read vulnerability. An attacker can leak information on the heap by constructing a zone file payload.

Patch / fix

  • ldns Debian 14, Debian 13, Debian 12 1.8.1-1

debian advisories DEBIAN-CVE-2020-19860

  • ldns Ubuntu 18.04 LTS 1.7.0-3ubuntu4.1
  • ldns Ubuntu Pro 16.04 LTS 1.6.17-8ubuntu0.1+esm1
  • ldns Ubuntu Pro 20.04 LTS 1.7.0-4.1ubuntu1+esm1
  • ldns Ubuntu Pro 22.04 LTS 1.7.1-2ubuntu4+esm1

ubuntu advisories UBUNTU-CVE-2020-19860

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • ldns SLE Real Time 15 SP2, SLE Module for Development Tools 15 SP3, SLE Module for Basesystem 15 SP3 1.7.0-4.6.1

suse advisories SUSE-SU-2022:0675-1

  • ldns openSUSE Tumbleweed 1.8.1-1.1
  • ldns openSUSE Leap 15.3 1.7.0-4.6.1

opensuse advisories openSUSE-SU-2024:11802-1openSUSE-SU-2022:0675-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2020-19860 updated cvss 6.5

ldns: heap overread vulnerability via zone file

  • Red Hat Enterprise Linux 6 ldns, ldns-python Red Hat Enterprise Linux 7 ldns, ldns-python
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 8 ldns, perl-ldns, ldns-utils, python3-ldns
    affected: no fix planned “Will not fix”
  • Red Hat Enterprise Linux 9 ldns, perl-ldns, ldns-utils, python3-ldns
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.21% chance of exploitation in the next 30 days, higher than 68% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/NLnetLabs/ldns/issues/50 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:P/I:N/A:N

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.