An out-of-bounds memory access in the generateDirectionalRuns() function in qtextengine.cpp in Qt qtbase 5.11.x and 5.12.x before 5.12.5 allows attackers to cause a denial of service by crashing an application via a text file containing many directional characters.
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.
| Link | Tags |
|---|---|
| https://bugreports.qt.io/browse/QTBUG-77819 | permissions required |
| https://codereview.qt-project.org/c/qt/qtbase/+/271889 | patch vendor advisory |
| https://bugs.launchpad.net/ubuntu/+source/qtbase-opensource-src/+bug/1848784 | issue tracking third party advisory |
| https://www.debian.org/security/2019/dsa-4556 | third party advisory vendor advisory |
| https://seclists.org/bugtraq/2019/Nov/4 | third party advisory mailing list |
| https://usn.ubuntu.com/4275-1/ | vendor advisory |
| https://security.gentoo.org/glsa/202003-60 | vendor advisory |