TLS server impersonation via skipped IP certificate check
Published Mar 27, 2024 · Updated Feb 13, 2025
Certificate check bypass in mbedTLS builds of curl and libcurl 8.5.0 through 8.6.0 allows remote attackers to impersonate IP-addressed TLS servers. In lib/vtls/mbedtls.c, mbed_connect_step1 called mbedtls_ssl_set_hostname only when an SNI name existed, so an IP literal skipped the host-binding check. An unauthenticated network attacker able to redirect a TLS connection can present a certificate for another host and read or alter application data.
Summary
What happened
Certificate check bypass in mbedTLS builds of curl and libcurl 8.5.0 through 8.6.0 allows remote attackers to impersonate IP-addressed TLS servers. In lib/vtls/mbedtls.c, mbed_connect_step1 called mbedtls_ssl_set_hostname only when an SNI name existed, so an IP literal skipped the host-binding check. An unauthenticated network attacker able to redirect a TLS connection can present a certificate for another host and read or alter application data.
The record
- CVE
- CVE-2024-2466
- Published
- Mar 27, 2024
- Updated
- Feb 13, 2025
- Vendor
- curl
- Product
- libcurl
- Classifications
- CWE-297, T1557
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 27, 2024CVE publishedPublication date reported by the CVE source.
- Feb 13, 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=8.5.0 <=8.6.0
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
- HackerOne report 2416725 certificate-check bypass proof of conceptproof of concept · unverified
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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