CVE-2020-19861

Exp

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.

Published: 2022-01-21 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-19861 is rated High Exploit Risk (70.9/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.49%). 1 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +1.17% over the last day, indicating growing attacker interest. Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2020-19861

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2020-19861

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.33% 1.49% +1.17%
2 2025-10-11 0.15% 0.33% +0.17%
3 2025-07-17 — 0.15% —

Full EPSS history (11 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-19861

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2020-19861

OS Trackers for CVE-2020-19861

vendor priority summary link
alpine high CVE-2020-19861: 1 source package rows (ldns); 1 state rows across 1 repos (3.12-main); fixed 0, open 1. https://security.alpinelinux.org/vuln/CVE-2020-19861
debian not yet assigned CVE-2020-19861 not yet assigned priority: Debian including 1 source packages (ldns), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 4, open 1. https://security-tracker.debian.org/tracker/CVE-2020-19861
redhat — — https://access.redhat.com/security/cve/CVE-2020-19861
suse medium CVE-2020-19861 severity moderate: SUSE including 18 source package names (ldns-1.7.0-4.6.1, ldns-1.8.1-1.1, …), 40 product×package rows across 19 product lines (SUSE Linux Enterprise Module for Basesystem 15 SP3, SUSE Linux Enterprise Module for Basesystem 15 SP4, … (19 product lines)): Fixed 40. https://www.suse.com/security/cve/CVE-2020-19861/
ubuntu medium CVE-2020-19861 medium priority: Ubuntu including 1 source packages (ldns), 14 status rows across 14 suites (bionic, focal, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 6, released 5, ignored 3. https://ubuntu.com/security/CVE-2020-19861

Affected software / configurations for CVE-2020-19861

Vendor Product Version Raw CPE
nlnetlabs ldns 1.7.1 cpe:2.3:a:nlnetlabs:ldns:1.7.1:*:*:*:*:*:*:*

References for CVE-2020-19861

URL Tags
https://cwe.mitre.org/data/definitions/126.html Third Party Advisory
https://github.com/NLnetLabs/ldns/issues/51 Exploit Issue Tracking Third Party Advisory
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