This indicates an attack attempt to exploit a Remote Code Execution in Werkzeug Debug Console.
The vulnerability is caused by a design weakness when the target application handles a maliciously crafted debug command. A remote attacker may be able to exploit this to execute arbitrary code within the context of the application, via a crafted debug command.
Werkzeug Debug Console 0.9.6 on Debian
Werkzeug Debug Console 0.9.6 on Centos
Werkzeug Debug Console 0.10 on Debian
System Compromise: Remote attackers can gain control of vulnerable systems.
Currently we are unaware of any vendor supplied patch for this issue.