Application crash via empty hostname buffer over-read
Published Jul 28, 2025 · Updated Jul 28, 2025
A buffer over-read in the openssl crate before 0.10.55 allows local users to crash an application by supplying an empty hostname. X509VerifyParamRef::set_host passes the empty Rust string's non-NUL-terminated pointer with length zero to X509_VERIFY_PARAM_set1_host, causing strlen to read arbitrary memory until a NUL byte. Reachability requires an application path that accepts an attacker-controlled empty hostname; observed consequences include memory exposure and a segmentation fault.
Summary
What happened
A buffer over-read in the openssl crate before 0.10.55 allows local users to crash an application by supplying an empty hostname. X509VerifyParamRef::set_host passes the empty Rust string's non-NUL-terminated pointer with length zero to X509_VERIFY_PARAM_set1_host, causing strlen to read arbitrary memory until a NUL byte. Reachability requires an application path that accepts an attacker-controlled empty hostname; observed consequences include memory exposure and a segmentation fault.
The record
- CVE
- CVE-2023-53159
- Published
- Jul 28, 2025
- Updated
- Jul 28, 2025
- Vendor
- Steven Fackler
- Product
- openssl
- Classifications
- CWE-126
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 28, 2025CVE publishedPublication date reported by the CVE source.
- Jul 28, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=0 <0.10.55
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
- Empty String domain crash reproducerproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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