Client fingerprinting via predictable TCP source ports
Published Jun 5, 2022 · Updated Aug 3, 2024
Information disclosure in the Linux kernel allows remote attackers to fingerprint clients through observable TCP source-port patterns. The IPv4 connection code uses an undersized table_perturb array, allowing repeated connections to reveal persistent hash collisions as a stable device identifier. Exploitation requires induced outbound connections to an observing server; source-port-rewriting NAT or forward proxies prevent tracking, and the identifier lasts until reboot.
Summary
What happened
Information disclosure in the Linux kernel allows remote attackers to fingerprint clients through observable TCP source-port patterns. The IPv4 connection code uses an undersized table_perturb array, allowing repeated connections to reveal persistent hash collisions as a stable device identifier. Exploitation requires induced outbound connections to an observing server; source-port-rewriting NAT or forward proxies prevent tracking, and the identifier lasts until reboot.
The record
- CVE
- CVE-2022-32296
- Published
- Jun 5, 2022
- Updated
- Aug 3, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-330
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 5, 2022CVE publishedPublication date reported by the CVE source.
- Aug 3, 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?
What conditions does exploitation require?
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
- RFC 6056 Device Trackerproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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