Links:
- The internet is now on fire:https://www.engadget.com/log4shell-vulnerability-log4j-155543990.html
- Blog post:https://blog.cloudflare.com/exploitation-of-cve-2021-44228-before-public-disclosure-and-evolution-of-waf-evasion-patterns/
- Expecting to be down for weeks:https://www.darkreading.com/attacks-breaches/kronos-suffers-ransomware-attack-expects-full-restoration-to-take-weeks-
- Update for the Apache Log4j2 Issue:https://aws.amazon.com/security/security-bulletins/AWS-2021-006/
- Log4Shell Vulnerability Tester at log4shell.huntress.com:https://log4shell.huntress.com/
Transcript
Corey: This is the AWS Morning Brief: Security Edition. AWS is fond of saying security is job zero. That means it’s nobody in particular’s job, which means it falls to the rest of us. Just the news you need to know, none of the fluff.
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Corey: I think I owe the entire internet a massive apology. See, last week I titled the episode, “A Somehow Quiet Security Week.” This is the equivalent of climbing to the top of a mountain peak during a violent thunderstorm, then waving around a long metal rod. While cursing God.
So, long story short, the internet is now on fire due to a vulnerability in the log4j open-source logging library. Effectively, if you can get an arbitrary string into the logs of a system that uses a vulnerable version of the log4j library, it will make outbound network requests. It can potentially run arbitrary code.
The impact is massive and this one’s going to be with us for years. WAF is a partial solution, but the only real answer is to patch to an updated version, or change a bunch of config options, or disallow affected systems from making outbound connections. Further, due to how thoroughly embedded in basically everything it is—like S3; more on that in a bit—a whole raft of software you run may very well be using this without your knowledge. This is, to be clear, freaking wild. I am deeply sorry for taunting fate last week. The rest of this issue of course talks entirely about this one enormous concern.
Corey: This episode is sponsored in part by my friends at Cloud Academy. Something special for you folks: if you missed their offer on Black Friday or Cyber Monday or whatever day of the week doing sales it is, good news, they’ve opened up their Black Friday promotion for a very limited time. Same deal: $100 off a yearly plan, 249 bucks a year for the highest quality cloud and tech skills content. Nobody else is going to get this, and you have to act now because they have assured me this is not going to last for much longer. Go to cloudacademy.com, hit the ‘Start Free Trial’ button on the homepage and use the promo code, ‘CLOUD’ when checking out. That’s C-L-O-U-D. Like loud—what I am—with a C in front of it. They’ve got a free trial, too, so you’ll get seven days to try it out to make sure it really is a good fit. You’ve got nothing to lose except your ignorance about cloud. My thanks to Cloud Academy once again for sponsoring my ridiculous nonsense.
Cloudflare has a blog post talking about the timeline of what they see as a global observer of exploitation attempts of this nonsense. They’re automatically shooting it down for all of their customers and users—to be clear, if you’re not paying for a service you are not its customer, you’re a marketing expense—and they’re doing this as part of the standard service they provide. Meanwhile AWS’s WAF has added the ruleset to its AWSManagedRulesKnownBadInputsRuleSet—all one word—managed rules—wait a minute; they named it that? Oh, AWS. You sad, ridiculous service-naming cloud. But yeah, you have to enable AWS WAF, for which there is effectively no free tier, and configure this rule to get its protection, as I read AWS’s original update. I’m sometimes asked why I use CloudFlare as my CDN instead of AWS’s offerings. Well, now you know.
Also, Kronos, an HR services firm, won the ransomware timing lottery. They’re expecting to be down for weeks, but due to the log4shell—which is what they’re calling this exploit: The log4shell problem—absolutely nobody is paying attention to companies that are having ransomware problems or data breaches. Good job, Kronos.
Now, what did AWS have to say? Well, they have an ongoing “Update for the Apache Log4j2 Issue” and they’ve been updating it as they go. But at the time of this recording, AWS is a Java shop, to my understanding.
That means that basically everything internet-facing at AWS—which is, you know, more or less everything they sell—has some risk exposure to this vulnerability. And AWS has moved with a speed that can only be described as astonishing, and mitigated this on their managed services in a timeline I wouldn’t have previously believed possible given the scope and scale here. This is the best possible argument to make for using higher-level managed services instead of building your own things on top of EC2. I just hope they’re classy enough not to use that as a marketing talking point.
And for the tool of the week, the Log4Shell Vulnerability Tester at log4shell.huntress.com automatically generates a string and then lets you know when that is exploited by this vulnerability what systems are connecting to is. Don’t misuse it obviously, but it’s great for validating whether a certain code path in your environment is vulnerable. And that’s what happened last week in AWS Security, and I just want to say again how deeply, deeply sorry I am for taunting fate and making everyone’s year suck. I’ll talk to you next week, if I live.
Corey: Thank you for listening to the AWS Morning Brief: Security Edition with the latest in AWS security that actually matters. Ple...
