#VU94613 Time-of-check Time-of-use (TOCTOU) Race Condition in Qt - CVE-2024-39936

Vulnerability identifier: #VU94613

Vulnerability risk: Low

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

CVE-ID: CVE-2024-39936

CWE-ID: CWE-367

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Qt
Universal components / Libraries / Scripting languages

Vendor: Trolltech

Description

The vulnerability allows a remote attacker to bypass implemented security restrictions.

The vulnerability exists due to a race condition in HTTP2 support when establishing an encrypted connection. A remote attacker can potentially force the application to send data before the encrypted() signal, leading to potential information disclosure.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Qt: 5.0 - 5.0.2, 5.1 - 5.15.17, 5.2 - 5.2.2, 5.3 - 5.3.2, 5.4 - 5.4.2, 5.5 - 5.5.1, 5.6 - 5.6.4, 5.7 - 5.7.1, 5.8 - 5.8.0, 5.9 - 5.9.9, 6.0 - 6.0.4, 6.1.0 - 6.1.3, 6.2.0 - 6.2.12, 6.3.0 - 6.3.2, 6.4.0, 6.4.1, 6.4.2, 6.4.3, 6.5.0 - 6.5.3, 6.6.0 - 6.6.3, 6.7.0 - 6.7.2

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External links
https://codereview.qt-project.org/c/qt/qtbase/+/571601

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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.