Information exposure via null-byte URL truncation
Published Apr 1, 2020 · Updated Sep 17, 2024
Null-byte truncation in PHP 7.2.x before 7.2.29, 7.3.x before 7.3.16, and 7.4.x before 7.4.4 allows attackers to redirect get_headers() requests. In ext/standard/url.c, get_headers() accepted an arbitrary string and passed it to a C-backed stream opener, which treated the first null byte as the end of the URL. A consuming application must pass attacker-controlled URL input; suffix validation can then approve one host while PHP contacts another, exposing request data or accepting attacker-controlled headers.
Summary
What happened
Null-byte truncation in PHP 7.2.x before 7.2.29, 7.3.x before 7.3.16, and 7.4.x before 7.4.4 allows attackers to redirect get_headers() requests. In ext/standard/url.c, get_headers() accepted an arbitrary string and passed it to a C-backed stream opener, which treated the first null byte as the end of the URL. A consuming application must pass attacker-controlled URL input; suffix validation can then approve one host while PHP contacts another, exposing request data or accepting attacker-controlled headers.
The record
- CVE
- CVE-2020-7066
- Published
- Apr 1, 2020
- Updated
- Sep 17, 2024
- Vendor
- The PHP Group
- Product
- PHP
- Classifications
- CWE-170, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 1, 2020CVE publishedPublication date reported by the CVE source.
- Sep 17, 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=7.2.x below 7.2.29
- Affected versionversion=7.3.x below 7.3.16
- Affected versionversion=7.4.x below 7.4.4
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
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.
Public exploit references
- PHP security bug 79329 test scriptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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