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Leaked NSA Tools Incriminated in Cisco Firewall Attacks

Some of Cisco's firewall appliance products have been targeted by purportedly leaked U.S. National Security Agency (NSA) hacking tools, the networking giant said last week.

The targeted firewalls include Cisco's current Adaptive Security Appliance (ASA) and its deprecated PIX products. Cisco ended PIX sales in 2009. The Cisco Product Security Incident Response team investigated disclosures by the "Shadow Brokers," a hacking entity that has been auctioning off exploit code used by the "Equation Group." Supposedly, the Equation Group is a reference to the NSA.

The Cisco team published a summary of two vulnerabilities at this page. Cisco identified eight exploit tools released by the Shadow Brokers, noting that three of the tools (ExtraBacon, EpicBanana and JetFlow) have references to Cisco products. The code used in the stolen tools is "dated around 2013 or older," Cisco noted, in a blog post.

A New York Times article speculated that the 2013 date of the exploit files reflects NSA security measures taken around that time. The idea is that the NSA took additional measures at that time after press disclosures of NSA documents leaked by former NSA contractor and whistleblower Edward Snowden.

The two targeted Cisco firewall flaws both could enable remote code execution attacks. One of the flaws, targeted by ExtraBacon, is a newly discovered exploit in Cisco ASA. In response, Cisco released signatures to detect the problem, but it hasn't issued a fix yet.

The other exploit is an ASA CLI defect that Cisco patched in 2011. It's targeted by EpicBanana and could lead to denial-of-service attacks. The JetFlow hacking tool is used by EpicBanana, but its purpose wasn't explained.

A security researcher has claimed that another hacking tool up for auction, called "BenignCertain," also targets Cisco PIX products, potentially enabling private key discovery, as noted in this Motherboard story.

An article by The Intercept offered evidence that at least one of the tools up for action, called "SecondDate," really is a leaked NSA hacking tool. That tool uses a specific name for a tracing string that's referenced in a new NSA document leaked by Snowden. SecondDate is designed to "intercept Web requests" and point browsers to malware-infected NSA Web servers, the article explained.

The purportedly leaked NSA hacking tools likely target flaws in other security products as well. An Ars Technica article suggested that a Fortinet FortiGate buffer overflow vulnerability was targeted by EgregiousBlunder, another hacking tool that's alleged to originate from the NSA.

Commenting via Twitter, Snowden last week noted that these flaws in U.S. networks went unaddressed from more than three years to support NSA offensive purposes. However, "the inevitable consequence of maintaining known vulnerabilities in US products is their discovery by enemies."