Vulnerability identifier: #VU22305

Vulnerability risk: High

CVSSv3.1: 7.7 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-16239

CWE-ID: CWE-119

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
OpenConnect VPN Client
Client/Desktop applications / Other client software

Vendor: OpenConnect

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to a boundary in the process_http_response when processing HTTP responses. A remote attacker that controls a malicious HTTP server can trick the victim to visit a malicious website, send an HTTP response with crafted chunk sizes for HTTP chunked encoding, trigger memory corruption and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation
Install update from vendor's website.

Vulnerable software versions

OpenConnect VPN Client: 0.90 - 8.04

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External links
http://lists.infradead.org/pipermail/openconnect-devel/2019-September/005412.html
http://t2.fi/schedule/2019/

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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.