Multiple buffer overflows in Sun Java Web Start in JDK and JRE 6 before Update 4, JDK and JRE 5.0 before Update 16, and SDK and JRE 1.4.x before 1.4.2_18 allow context-dependent attackers to gain privileges via an untrusted application, as demonstrated by (a) an application that grants itself privileges to (1) read local files, (2) write to local files, or (3) execute local programs; and as demonstrated by (b) a long value associated with a java-vm-args attribute in a j2se tag in a JNLP file, which triggers a stack-based buffer overflow in the GetVMArgsOption function; aka CR 6557220.