#VU22483 Out-of-bounds read in Qt - CVE-2019-18281

Vulnerability identifier: #VU22483

Vulnerability risk: Low

CVSSv4.0: 1.2 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2019-18281

CWE-ID: CWE-125

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Qt
Universal components / Libraries / Scripting languages

Vendor: Trolltech

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a boundary condition within the generateDirectionalRuns() function in qtextengine.cpp in Qt qtbase. A remote attacker can create a specially crafted file, containing many directional characters, trick the victim into opening it, trigger out-of-bounds read error and crash the affected application.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Qt: 5.11.0 - 5.12.4

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External links
https://bugreports.qt.io/browse/QTBUG-77819
https://bugs.launchpad.net/ubuntu/+source/qtbase-opensource-src/+bug/1848784
https://codereview.qt-project.org/c/qt/qtbase/+/271889

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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.