Heap data disclosure via unvalidated NSEC3 salt length
Published Jan 21, 2022 · Updated Aug 4, 2024
Out-of-bounds read in NLnet Labs ldns 1.7.1 allows remote attackers to disclose heap data via a crafted NSEC3 record in a zone file. The ldns_nsec3_salt_data function trusts the NSEC3 salt length and passes 0xfe minus the salt RDF size to memcpy, causing it to read past the heap buffer. Exploitation requires ldns to parse the crafted zone data; the published impact is memory disclosure, with no integrity or availability impact.
Summary
What happened
Out-of-bounds read in NLnet Labs ldns 1.7.1 allows remote attackers to disclose heap data via a crafted NSEC3 record in a zone file. The ldns_nsec3_salt_data function trusts the NSEC3 salt length and passes 0xfe minus the salt RDF size to memcpy, causing it to read past the heap buffer. Exploitation requires ldns to parse the crafted zone data; the published impact is memory disclosure, with no integrity or availability impact.
The record
- CVE
- CVE-2020-19861
- Published
- Jan 21, 2022
- Updated
- Aug 4, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-125
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jan 21, 2022CVE publishedPublication date reported by the CVE source.
- Aug 4, 2024Record updatedLatest update available in the CVE record.
Exploitability
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What is affected?
Affected products and versions are unavailable in this record.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Malformed zone-file fuzz payloadproof of concept · unverified
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Technologies
Your stack
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Your stack
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