The XMLHttpRequest object in Qt before 4.8.4 enables http redirection to the file scheme, which allows man-in-the-middle attackers to force the read of arbitrary local files and possibly obtain sensitive information via a file: URL to a QML application.

The QSharedMemory class in Qt 5.0.0, 4.8.x before 4.8.5, 4.7.x before 4.7.6, and other versions including 4.4.0 uses weak permissions (world-readable and world-writable) for shared memory segments, which allows local users to read sensitive information or modify critical program data, as demonstrated by reading a pixmap being sent to an X server.

Off-by-one error in the QUtf8Decoder::toUnicode function in Trolltech Qt 3 allows context-dependent attackers to cause a denial of service (crash) via a crafted Unicode string that triggers a heap-based buffer overflow. NOTE: Qt 4 has the same error in the QUtf8Codec::convertToUnicode function, but it is not exploitable.

Integer overflow in Qt 3.3 before 3.3.7, 4.1 before 4.1.5, and 4.2 before 4.2.1, as used in the KDE khtml library, kdelibs 3.1.3, and possibly other packages, allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a crafted pixmap image.

Qt before 3.3.4 searches the BUILD_PREFIX directory, which could be world-writable, to load shared libraries regardless of the LD_LIBRARY_PATH environment variable, which allows local users to execute arbitrary programs.