April 13, 2024

It’s not typically {that a} zero-day vulnerability causes a community safety vendor to induce prospects to bodily take away and decommission a complete line of affected {hardware} — versus simply making use of software program updates. However consultants say that’s precisely what transpired this week with Barracuda Networks, as the corporate struggled to fight a sprawling malware risk which seems to have undermined its e-mail safety home equipment in such a basic approach that they’ll now not be safely up to date with software program fixes.

The Barracuda E-mail Safety Gateway (ESG) 900 equipment.

Campbell, Calif. primarily based Barracuda mentioned it employed incident response agency Mandiant on Could 18 after receiving stories about uncommon site visitors originating from its E-mail Safety Gateway (ESG) units, that are designed to take a seat on the fringe of a company’s community and scan all incoming and outgoing e-mail for malware.

On Could 19, Barracuda recognized that the malicious site visitors was making the most of a beforehand unknown vulnerability in its ESG home equipment, and on Could 20 the corporate pushed a patch for the flaw to all affected home equipment (CVE-2023-2868).

In its security advisory, Barracuda mentioned the vulnerability existed within the Barracuda software program element chargeable for screening attachments for malware. Extra alarmingly, the corporate mentioned it seems attackers first began exploiting the flaw in October 2022.

However on June 6, Barracuda immediately started urging its ESG prospects to wholesale rip out and change — not patch — affected home equipment.

“Impacted ESG home equipment have to be instantly changed no matter patch model stage,” the corporate’s advisory warned. “Barracuda’s suggestion presently is full substitute of the impacted ESG.”

In a press release, Barracuda mentioned will probably be offering the substitute product to impacted prospects for free of charge, and that not all ESG home equipment had been compromised.

“No different Barracuda product, together with our SaaS e-mail options, had been impacted by this vulnerability,” the corporate mentioned. “If an ESG equipment is displaying a notification within the Consumer Interface, the ESG equipment had indicators of compromise. If no notification is displayed, now we have no motive to imagine that the equipment has been compromised presently.”

However, the assertion says that “out of an abundance of warning and in furtherance of our containment technique, we suggest impacted prospects change their compromised equipment.”

“As of June 8, 2023, roughly 5% of lively ESG home equipment worldwide have proven any proof of recognized indicators of compromise as a result of vulnerability,” the assertion continues. “Regardless of deployment of further patches primarily based on recognized IOCs, we proceed to see proof of ongoing malware exercise on a subset of the compromised home equipment. Due to this fact, we wish prospects to interchange any compromised equipment with a brand new unaffected gadget.”

Rapid7‘s Caitlin Condon known as this outstanding flip of occasions “pretty beautiful,” and mentioned there look like roughly 11,000 weak ESG units nonetheless linked to the Web worldwide.

“The pivot from patch to complete substitute of affected units is pretty beautiful and implies the malware the risk actors deployed one way or the other achieves persistence at a low sufficient stage that even wiping the gadget wouldn’t eradicate attacker entry,” Condon wrote.

Barracuda mentioned the malware was recognized on a subset of home equipment that allowed the attackers persistent backdoor entry to the units, and that proof of information exfiltration was recognized on some programs.

Rapid7 mentioned it has seen no proof that attackers are utilizing the flaw to maneuver laterally inside sufferer networks. However which may be small comfort for Barracuda prospects now coming to phrases with the notion that overseas cyberspies in all probability have been hoovering up all their e-mail for months.

Nicholas Weaver, a researcher at College of California, Berkeley’s International Computer Science Institute (ICSI), mentioned it’s doubtless that the malware was in a position to corrupt the underlying firmware that powers the ESG units in some irreparable approach.

“One of many objectives of malware is to be laborious to take away, and this implies the malware compromised the firmware itself to make it actually laborious to take away and actually stealthy,” Weaver mentioned. “That’s not a ransomware actor, that’s a state actor. Why? As a result of a ransomware actor doesn’t care about that stage of entry. They don’t want it. In the event that they’re going for knowledge extortion, it’s extra like a smash-and-grab. In the event that they’re going for knowledge ransoming, they’re encrypting the info itself — not the machines.”

Along with changing units, Barracuda says ESG prospects must also rotate any credentials linked to the equipment(s), and verify for indicators of compromise relationship again to a minimum of October 2022 utilizing the community and endpoint indicators the corporate has released publicly.

Replace, June 9, 11:55 a.m. ET: Barracuda has issued an up to date assertion concerning the incident, parts of which at the moment are excerpted above.