#VU51821 Information disclosure in cURL - CVE-2021-22876

Vulnerability identifier: #VU51821

Vulnerability risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-22876

CWE-ID: CWE-200

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 gain access to potentially sensitive information.

The vulnerability exists due to libcurl does not strip off user credentials from the URL when automatically populating the Referer: HTTP request header field in outgoing HTTP requests and therefore risks leaking sensitive data to the server that is the target of the second HTTP request.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

cURL: 7.1 - 7.75.0

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External links
http://curl.haxx.se/docs/CVE-2021-22876.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.