Cleartext transfer via unshared HSTS cache
Published Feb 23, 2023 · Updated Mar 12, 2025
Cleartext transmission in curl 7.77.0 through 7.87.0 allows man-in-the-middle attackers to read data from serial HTTP transfers. The command-line tool creates a new easy handle for each URL without sharing the in-memory HSTS cache, so later handles miss policies learned earlier. Exploitation requires multiple URLs in one invocation with HSTS enabled, an HTTP URL after a policy-bearing HTTPS response, and network interception.
Summary
What happened
Cleartext transmission in curl 7.77.0 through 7.87.0 allows man-in-the-middle attackers to read data from serial HTTP transfers. The command-line tool creates a new easy handle for each URL without sharing the in-memory HSTS cache, so later handles miss policies learned earlier. Exploitation requires multiple URLs in one invocation with HSTS enabled, an HTTP URL after a policy-bearing HTTPS response, and network interception.
The record
- CVE
- CVE-2023-23914
- Published
- Feb 23, 2023
- Updated
- Mar 12, 2025
- Vendor
- curl
- Product
- curl
- Classifications
- CWE-319, T1557
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Feb 23, 2023CVE publishedPublication date reported by the CVE source.
- Mar 12, 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=Fixed in 7.88.0
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.
Weakness, pattern, technique
Public exploit references
- Upstream serial-transfer reproducerproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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