Deconstructing local and remote file inclusion attack vectors

Imperva released its latest Hacker Intelligence Initiative report exploring how Local and Remote File Inclusion (RFI/LFI) attacks enable hackers to execute malicious code and steal data through the manipulation of a company’s web server.

RFI/LFI attacks made up 21% of all application attacks observed by Imperva in its review of attacks across 40 applications from June – November 2011.

RFI and LFI attacks take advantage of vulnerable PHP Web application parameters by including a URL reference to remotely host arbitrary code, enabling remote execution.

“LFI and RFI are popular attack vectors for hackers because it is less known and extremely powerful when successful,” said Tal Be’ery, Imperva’s senior web researcher. “We observed that hacktivists and for-profit hackers utilized these techniques extensively in 2011, and we believe it is time for the security community to devote more attention to the issue.”

Highlights from the report include:

RFI/LFI “In the Wild” – A discussion of real-world RFI/LFI attacks, such as how LFI compromised 1.2M WordPress websites via a TimThumb vulnerability, provides the context needed into the importance of awareness of the technique.

RFI/LFI deconstructed – A visual step-by-step technical analysis of an RFI-infected file demonstrates how shell code obfuscates the attack vector, highlighting how it can avoid traditional detection and mitigation techniques.

Evolution of RFI/LFI – From Remote File Inclusion to Local File Inclusion, hackers continue to develop new attack vectors to evade anti-malware by splitting across multiple fields in infected files.

Techniques to mitigate RFI/LFI – Introduces a novel approach to mitigate against RFI attacks by utilizing a shell hosting feed.

The complete report is available here.