Vulnerability Monitor

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CVE-2016-3739


The (1) mbed_connect_step1 function in lib/vtls/mbedtls.c and (2) polarssl_connect_step1 function in lib/vtls/polarssl.c in cURL and libcurl before 7.49.0, when using SSLv3 or making a TLS connection to a URL that uses a numerical IP address, allow remote attackers to spoof servers via an arbitrary valid certificate.


Security Impact Summary

This vulnerability carries a MEDIUM severity rating with a CVSS v3.1 score of 5.3, indicating it can be exploited remotely over the network but requires specific conditions to be met though user interaction is required and does not require pre-existing privileges . The vulnerability impacts integrity (unauthorized modifications), for affected systems. Impacting 1 product from haxx organizations running these solutions should prioritize assessment and patching.

Historical Context

First disclosed in 2016, this vulnerability was reported during a period defined by widespread IoT adoption challenges, mobile security concerns, and the emergence of advanced persistent threat (APT) techniques. Contemporary mitigation strategies focused on secure development practices and third-party component vetting.


Published

2016-05-20T14:59:05.450

Last Modified

2025-04-12T10:46:40.837

Status

Deferred

Source

[email protected]

Severity

CVSSv3.0: 5.3 (MEDIUM)

CVSSv2 Vector

AV:N/AC:H/Au:N/C:N/I:P/A:N

  • Access Vector: NETWORK
  • Access Complexity: HIGH
  • Authentication: NONE
  • Confidentiality Impact: NONE
  • Integrity Impact: PARTIAL
  • Availability Impact: NONE
Exploitability Score

4.9

Impact Score

2.9

Weaknesses
  • Type: Primary
    CWE-20

Affected Vendors & Products
Type Vendor Product Version/Range Vulnerable?
Application haxx curl 7.21.0 Yes
Application haxx curl 7.21.1 Yes
Application haxx curl 7.21.2 Yes
Application haxx curl 7.21.3 Yes
Application haxx curl 7.21.4 Yes
Application haxx curl 7.21.5 Yes
Application haxx curl 7.21.6 Yes
Application haxx curl 7.21.7 Yes
Application haxx curl 7.22.0 Yes
Application haxx curl 7.23.0 Yes
Application haxx curl 7.23.1 Yes
Application haxx curl 7.24.0 Yes
Application haxx curl 7.25.0 Yes
Application haxx curl 7.26.0 Yes
Application haxx curl 7.27.0 Yes
Application haxx curl 7.28.0 Yes
Application haxx curl 7.28.1 Yes
Application haxx curl 7.29.0 Yes
Application haxx curl 7.30.0 Yes
Application haxx curl 7.31.0 Yes
Application haxx curl 7.32.0 Yes
Application haxx curl 7.33.0 Yes
Application haxx curl 7.34.0 Yes
Application haxx curl 7.35.0 Yes
Application haxx curl 7.36.0 Yes
Application haxx curl 7.38.0 Yes
Application haxx curl 7.39.0 Yes
Application haxx curl 7.40.0 Yes
Application haxx curl 7.41.0 Yes
Application haxx curl 7.42.0 Yes
Application haxx curl 7.42.1 Yes
Application haxx curl 7.43.0 Yes
Application haxx curl 7.44.0 Yes
Application haxx curl 7.45.0 Yes
Application haxx curl 7.46.0 Yes
Application haxx curl 7.47.0 Yes
Application haxx curl 7.48.0 Yes

References

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For haxx's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.