Process-memory disclosure via oversized uninitialized packet buffers
Published May 20, 2021 · Updated Sep 16, 2024
Information disclosure in dns-packet before 5.2.2 allows remote authenticated users to read process memory through crafted invalid domain names. The name encodingLength routine counts terminal dots that name.encode trims, so allocUnsafe creates a packet buffer larger than the bytes written. An application must encode an attacker-controlled invalid name and send the resulting packet over an unencrypted network; only residual process-memory bytes are exposed.
Summary
What happened
Information disclosure in dns-packet before 5.2.2 allows remote authenticated users to read process memory through crafted invalid domain names. The name encodingLength routine counts terminal dots that name.encode trims, so allocUnsafe creates a packet buffer larger than the bytes written. An application must encode an attacker-controlled invalid name and send the resulting packet over an unencrypted network; only residual process-memory bytes are exposed.
The record
- CVE
- CVE-2021-23386
- Published
- May 20, 2021
- Updated
- Sep 16, 2024
- Vendor
- Mathias Buus
- Product
- dns-packet
- Classifications
- CWE-909, CWE-201, T1005
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- May 20, 2021CVE publishedPublication date reported by the CVE source.
- Sep 16, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=unspecified <5.2.2
What conditions does exploitation require?
What is affected?
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
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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