← Vulnerability feed

Vulnerability record · CVE-2020-19861 · published 21 January 2022

CVE-2020-19861: Nlnetlabs ldns out-of-bounds read vulnerability

Nlnetlabs · Ldns

When a zone file in ldns 1.7.1 is parsed, the function ldns_nsec3_salt_data is too trusted for the length value obtained from the zone file. When the memcpy is copied, the 0xfe - ldns_rdf_size(salt_rdf) byte data can be copied, causing heap overflow information leakage.

7.5 CVSS 3.1 High EPSS 1.5% · top 26.9% CWE-125 · Out-of-bounds read
7.5CVSS 3.1 base score, v2 5.0
1.5%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
4References, 2 tagged exploit
17 Jun 2026Last modified by NVD

Description

When a zone file in ldns 1.7.1 is parsed, the function ldns_nsec3_salt_data is too trusted for the length value obtained from the zone file. When the memcpy is copied, the 0xfe - ldns_rdf_size(salt_rdf) byte data can be copied, causing heap overflow information leakage.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://cwe.mitre.org/data/definitions/126.html Third Party Advisory
https://github.com/NLnetLabs/ldns/issues/51 ExploitIssue TrackingThird Party Advisory
https://cwe.mitre.org/data/definitions/126.html Third Party Advisory
https://github.com/NLnetLabs/ldns/issues/51 ExploitIssue TrackingThird Party Advisory

Track CVE-2020-19861 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2017-1000231Nlnetlabs ldns double free vulnerabilityA double-free vulnerability in parse.c in ldns 1.7.0 have unspecified impact and attack vectors.EPSS 2.7%9.8CVE-2017-1000232Nlnetlabs ldns double free vulnerabilityA double-free vulnerability in str2host.c in ldns 1.7.0 have unspecified impact and attack vectors.EPSS 2.3%8.2CVE-2026-10846Nlnetlabs ldns origin validation error vulnerabilityNLnet Labs ldns 1.2.0 up to and including versions 1.9.0, when used in applications as (stub) resolver over UDP, lacks matching the query destination…EPSS 0.15%6.8CVE-2011-3581Nlnetlabs ldns memory buffer overflow vulnerabilityHeap-based buffer overflow in the ldns_rr_new_frm_str_internal function in ldns before 1.6.11 allows remote attackers to cause a denial of service (c…EPSS 4.1%6.5CVE-2020-19860Nlnetlabs ldns out-of-bounds read vulnerabilityWhen 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 …EPSS 1.3%6.4CVE-2009-1086Nlnetlabs ldns vulnerabilityHeap-based buffer overflow in the ldns_rr_new_frm_str_internal function in ldns 1.4.x allows remote attackers to cause a denial of service (memory co…EPSS 3.5%2.1CVE-2014-3209Nlnetlabs ldns permissions and access controls vulnerabilityThe ldns-keygen tool in ldns 1.6.x uses the current umask to set the privileges of the private key, which might allow local users to obtain the priva…EPSS 0.38%8.8CVE-2026-11645Google Chrome V8 out-of-bounds read and write enables sandbox code executionGoogle Chrome before 149.0.7827.103 contains an out-of-bounds read and write in the V8 JavaScript engine. A crafted HTML page can trigger the memory …KEVEPSS 2.2%analysed

Source: NIST National Vulnerability Database (record CVE-2020-19861), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.