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 QSslSocket::sslErrors function in Qt before 4.6.5, 4.7.x before 4.7.6, 4.8.x before 4.8.5, when using certain versions of openSSL, uses an "incompatible structure layout" that can read memory from the wrong location, which causes Qt to report an incorrect error when certificate validation fails and might cause users to make unsafe security decisions to accept a certificate.

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.

Buffer overflow in the TIFF reader in gui/image/qtiffhandler.cpp in Qt 4.7.4 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via the TIFFTAG_SAMPLESPERPIXEL tag in a greyscale TIFF image with multiple samples per pixel.

src/network/ssl/qsslcertificate.cpp in Nokia Trolltech Qt 4.x does not properly handle a '\0' character in a domain name in the Subject Alternative Name field of an X.509 certificate, which allows man-in-the-middle attackers to spoof arbitrary SSL servers via a crafted certificate issued by a legitimate Certification Authority, a related issue to CVE-2009-2408.