PureSec Discloses Vulnerabilities in OpenWhisk Serverless Runtime

A pair of flaws in the Apache OpenWhisk Serverless platform could have exposed users to risk.

PureSec OpenWhisk Vulnerabilities

PureSec disclosed on July 24 that it reported a pair of vulnerabilities in the Apache OpenWhisk serverless runtime that potentially could have left users at risk.

Apache OpenWhisk is an open-source project that serves as the basis for the IBM Cloud Functions service as well. The two flaws—CVE-2018-11756 and CVE-2018-11757—could have enabled a remote attacker to overwrite the source code of a vulnerable function. OpenWhisk has patched the issues, and IBM is downplaying the overall risk.

"After this very low-risk vulnerability was reported to the Apache open community, IBM updated our code within a week to prevent this minor flaw from impacting users of OpenWhisk," Michael Behrendt, IBM Distinguished Engineer, IBM Cloud Functions, told eWEEK. "This quick response reflects the many benefits of building and operating technology in the open community, as improvements can be found and vulnerabilities corrected rapidly."

OpenWhisk is a serverless technology that is also sometimes referred to as functions-as-a-service, or event-driven programming. In a serverless model, programmatic code, or "functions," are executed on ephemeral containers that only exist to serve a given function. Other popular serverless platforms include AWS Lambda and Google Cloud Functions. Ory Segal, founder and CTO of PureSec, said his company is in the process of conducting a comparative analysis review of all popular serverless platforms.

"One of the issues we wanted to check was the isolation capabilities, as well as the immutability, or lack thereof, of function code," Segal told eWEEK.

Of particular note, Segal warned that prior to the patch being made to OpenWhisk, an unauthenticated end user could have exploited the vulnerabilities his firm discovered. That said, there is no indication that OpenWhisk was ever exploited by attackers using those vulnerabilities, he added.

"Serverless security research and exploitation techniques are pretty cutting edge, and PureSec is definitely pioneering in this field," Segal said. "We haven't seen anything remotely relevant on the internet and on the dark web, which we monitor constantly."

PureSec announced the general availability of its serverless security platform on July 19. The platform includes static analysis algorithms to analyze functions during the development phase and a serverless applications firewall to control the perimeter of functions once invoked. There are other vendors that provide serverless security scanning, including Twistlock, which announced its serverless capabilities on June 19.

The team at PureSec believes that serverless is the future of cloud computing, bringing benefits for developers and operators, Segal said.

"When it comes to security, there are massive benefits to serverless over more traditional architectures," he said. "The fact that functions are ephemeral, and don't stay around for a long time, also reduces the ability to use their infrastructure for long-running malicious activities."

That said, Segal emphasized that serverless is not a panacea for application security. Developers are still responsible for building robust and secure serverless applications.

"A vulnerable serverless application can still be abused and exploited, just like any other application," he said. "The main difference is that you cannot use any of the traditional application security solutions such as WAFs or RASP, which is why we founded PureSec." 

Sean Michael Kerner is a senior editor at eWEEK and InternetNews.com. Follow him on Twitter @TechJournalist.

Sean Michael Kerner

Sean Michael Kerner

Sean Michael Kerner is an Internet consultant, strategist, and contributor to several leading IT business web sites.