#VU76237 Improper certificate validation in cURL - CVE-2023-28321

Vulnerability identifier: #VU76237

Vulnerability risk: Medium

CVSSv4.0: 1.7 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2023-28321

CWE-ID: CWE-295

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
cURL
Client/Desktop applications / Other client software

Vendor: curl.haxx.se

Description

The vulnerability allows a remote attacker to perform MitM attack.

The vulnerability exists due to improper certificate validation when matching wildcards in TLS certificates for IDN names. A remote attacker crate a specially crafted certificate that will be considered trusted by the library.

Successful exploitation of the vulnerability requires that curl is built to use OpenSSL, Schannel or Gskit.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

cURL: 7.12 - 8.0.1

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External links
http://curl.haxx.se/docs/CVE-2023-28321.html

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.