April 13, 2024

It’s not usually {that a} zero-day vulnerability causes a community safety vendor to induce clients 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 menace which seems to have undermined its electronic mail safety home equipment in such a basic method that they’ll now not be safely up to date with software program fixes.

The Barracuda Electronic mail Safety Gateway (ESG) 900 equipment.

Campbell, Calif. based mostly Barracuda mentioned it employed incident response agency Mandiant on Might 18 after receiving stories about uncommon visitors originating from its Electronic 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 electronic mail for malware.

On Might 19, Barracuda recognized that the malicious visitors was making the most of a beforehand unknown vulnerability in its ESG home equipment, and on Might 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 out of the blue started urging its ESG clients to wholesale rip out and exchange — not patch — affected home equipment.

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

In a press release, Barracuda mentioned will probably be offering the substitute product to impacted clients without charge, and that not all ESG home equipment had been compromised.

“No different Barracuda product, together with our SaaS electronic 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, we have now no motive to consider that the equipment has been compromised presently.”

Nonetheless, the assertion says that “out of an abundance of warning and in furtherance of our containment technique, we advocate impacted clients exchange 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 because of the vulnerability,” the assertion continues. “Regardless of deployment of extra patches based mostly on recognized IOCs, we proceed to see proof of ongoing malware exercise on a subset of the compromised home equipment. Subsequently, we wish clients to interchange any compromised equipment with a brand new unaffected machine.”

Rapid7‘s Caitlin Condon known as this exceptional flip of occasions “pretty gorgeous,” and mentioned there look like roughly 11,000 susceptible ESG units nonetheless related to the Web worldwide.

“The pivot from patch to whole substitute of affected units is pretty gorgeous and implies the malware the menace actors deployed by some means achieves persistence at a low sufficient degree that even wiping the machine 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 knowledge exfiltration was recognized on some techniques.

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 clients now coming to phrases with the notion that overseas cyberspies in all probability have been hoovering up all their electronic mail for months.

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

“One of many targets of malware is to be laborious to take away, and this means 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 degree of entry. They don’t want it. In the event that they’re going for information extortion, it’s extra like a smash-and-grab. In the event that they’re going for information ransoming, they’re encrypting the info itself — not the machines.”

Along with changing units, Barracuda says ESG clients also needs to rotate any credentials related to the equipment(s), and test for indicators of compromise relationship again to not less than 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 in regards to the incident, parts of which at the moment are excerpted above.