CVE-2020-19861
CVE-2020-19861 is a high-severity vulnerability in Nlnetlabs Ldns with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-125.
Key facts
- Severity: High (CVSS 3.x base score 7.5)
- CVSS v2: 5.0
- EPSS exploit prediction: 1% (71st percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-125
- Affected product: Nlnetlabs Ldns
- Published:
- Last modified:
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.
Frequently asked questions
- What is CVE-2020-19861?
- 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.
- How severe is CVE-2020-19861?
- CVE-2020-19861 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
- Is CVE-2020-19861 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (71st percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2020-19861?
- CVE-2020-19861 affects Nlnetlabs Ldns. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2020-19861?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- When was CVE-2020-19861 published?
- CVE-2020-19861 was published on 2022-01-21 and last updated on 2026-06-17.
References
Affected products (1)
- cpe:2.3:a:nlnetlabs:ldns:1.7.1:*:*:*:*:*:*:*
More vulnerabilities in Nlnetlabs Ldns
- CVE-2017-1000232 — Critical (CVSS 9.8): A double-free vulnerability in str2host.c in ldns 1.7.0 have unspecified impact and attack vectors.
- CVE-2017-1000231 — Critical (CVSS 9.8): A double-free vulnerability in parse.c in ldns 1.7.0 have unspecified impact and attack vectors.
- CVE-2026-10846 — High (CVSS 7.5): NLnet Labs ldns 1.2.0 up to and including versions 1.9.0, when used in applications as (stub) resolver over UDP, lacks…
- CVE-2011-3581 — Medium (CVSS 6.8): Heap-based buffer overflow in the ldns_rr_new_frm_str_internal function in ldns before 1.6.11 allows remote attackers…
- CVE-2020-19860 — Medium (CVSS 6.5): 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…
- CVE-2009-1086 — Medium (CVSS 6.4): Heap-based buffer overflow in the ldns_rr_new_frm_str_internal function in ldns 1.4.x allows remote attackers to cause…
All CVEs affecting Nlnetlabs Ldns →
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