#VU66866 Out-of-bounds read in Qt - CVE-2021-3481

Vulnerability identifier: #VU66866

Vulnerability risk: Medium

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

CVE-ID: CVE-2021-3481

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 gain access to potentially sensitive information or crash the application.

The vulnerability exists due to a boundary condition within the QRadialFetchSimd in qt/qtbase/src/gui/painting/qdrawhelper_p.h in Qt/Qtbase when rendering and displaying a crafted Scalable Vector Graphics (SVG) file. A remote attacker can create a specially crafted SVG file, trick the victim into opening it, trigger out-of-bounds read error and read contents of memory on the system or crash the application.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Qt: 5.12 - 5.15.3, 6.0.0 - 6.0.2

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External links
https://codereview.qt-project.org/c/qt/qtsvg/+/337646
https://bugzilla.redhat.com/show_bug.cgi?id=1931444
https://bugreports.qt.io/browse/QTBUG-91507
https://access.redhat.com/security/cve/CVE-2021-3481

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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.