HTTP request injection via unchecked header values
Published Jan 20, 2023 · Updated Apr 2, 2025
CRLF injection in Swift Foundation before 5.7.3 allows attackers to inject HTTP headers or requests through URLRequest values. URLRequest header setters accepted CR and LF characters, and URLSession serialized those values into outbound HTTP messages without rejecting invalid line breaks. Exploitation requires a consuming application to place attacker-controlled, unsanitized data in a header value; successful injection can add headers or a second request to an intermediary or backend server.
Summary
What happened
CRLF injection in Swift Foundation before 5.7.3 allows attackers to inject HTTP headers or requests through URLRequest values. URLRequest header setters accepted CR and LF characters, and URLSession serialized those values into outbound HTTP messages without rejecting invalid line breaks. Exploitation requires a consuming application to place attacker-controlled, unsanitized data in a header value; successful injection can add headers or a second request to an intermediary or backend server.
The record
- CVE
- CVE-2022-3918
- Published
- Jan 20, 2023
- Updated
- Apr 2, 2025
- Vendor
- Swift Project
- Product
- Swift Foundation
- Classifications
- CWE-113, CAPEC-105
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Jan 20, 2023CVE publishedPublication date reported by the CVE source.
- Apr 2, 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=unspecified <=5.7.2
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
- Upstream CRLF request-splitting demonstrationproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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