The major thing to look for is .desktop files that trigger off of MimeTypes, yet actually run the target file. For example /usr/share/applications/openjdk-6-java.desktop:
... Exec=/usr/lib/jvm/java-6-openjdk/bin/java -jar ... MimeType=application/x-java-archive;application/java-archive;application/x-jar;
This leads to executing the JAR file, even when it lacks the execute bit.
The major thing to look for is .desktop files that trigger off of MimeTypes, yet actually run the target file. For example /usr/share/ applications/ openjdk- 6-java. desktop:
... lib/jvm/ java-6- openjdk/ bin/java -jar application/ x-java- archive; application/ java-archive; application/ x-jar;
Exec=/usr/
...
MimeType=
This leads to executing the JAR file, even when it lacks the execute bit.