Software security is an idea implemented to protect software against malicious attack and other hacker risks so that the software continues to function correctly under such potential risks. Security is necessary to provide integrity, authentication and availability.
Any compromise to integrity, authentication and availability makes a software unsecure. Software systems can be attacked to steal information, monitor content, introduce vulnerabilities and damage the behavior of software. Malware can cause denial of service or crash the system itself.
Buffer overflow, stack overflow, command injection and SQL injections are the most common attacks on the software.
Buffer and stack overflow attacks overwrite the contents of the heap or stack respectively by writing extra bytes.
Command injection can be achieved on the software code when system commands are used predominantly. New system commands are appended to existing commands by the malicious attack. Sometimes system command may stop services and cause DoS.
SQL injections use malicious SQL code to retrieve or modify important information from database servers. SQL injections can be used to bypass login credentials. Sometimes SQL injections fetch important information from a database or delete all important data from a database.
The only way to avoid such attacks is to practice good programming techniques. System-level security can be provided using better firewalls. Using intrusion detection and prevention can also aid in stopping attackers from easy access to the system.