Several vulnerabilities have been discovered in qt4-x11, a cross-platform C++ application framework. The Common Vulnerabilities and Exposures project identifies the following problems: Array index error in the insertItemBefore method in WebKit, as used in qt4-x11, allows remote attackers to execute arbitrary code. The JavaScript garbage collector in WebKit, as used in qt4-x11 does not properly handle allocation failures, which allows remote attackers to execute arbitrary code or cause a denial of service via a crafted HTML document that triggers write access to an "offset of a NULL pointer. Use-after-free vulnerability in WebKit, as used in qt4-x11, allows remote attackers to execute arbitrary code or cause a denial of service by setting an unspecified property of an HTML tag that causes child elements to be freed and later accessed when an HTML error occurs. WebKit in qt4-x11 does not initialize a pointer during handling of a Cascading Style Sheets attr function call with a large numerical argument, which allows remote attackers to execute arbitrary code or cause a denial of service via a crafted HTML document. The XSL stylesheet implementation in WebKit, as used in qt4-x11 does not properly handle XML external entities, which allows remote attackers to read arbitrary files via a crafted DTD. WebKit in qt4-x11 does not properly initialize memory for Attr DOM objects, which allows remote attackers to execute arbitrary code or cause a denial of service via a crafted HTML document. WebKit in qt4-x11 does not prevent remote loading of local Java applets, which allows remote attackers to execute arbitrary code, gain privileges, or obtain sensitive information via an APPLET or OBJECT element. The XSLT functionality in WebKit, as used in qt4-x11 does not properly implement the document function, which allows remote attackers to read arbitrary local files and files from different security zones. WebKit in qt4-x11 does not properly handle numeric character references, which allows remote attackers to execute arbitrary code or cause a denial of service via a crafted HTML document. qt4-x11 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. The oldstable distribution is not affected by these problems.