Log4j Vulnerability - What do you need to know?

2 years ago
11 December 2021
32 comments
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+20

MicoolPaul
Veeam Legend, Veeam Vanguard
2210 comments

Hi Everyone,

Vulnerabilities wait for no-one, so whilst some are enjoying a weekend off, others are patching to protect against the latest risk. Log4j.

This post has two objectives. Firstly I’m sharing my write up regarding the issues I’m aware DO have an impact to VMware, secondly what does this mean to the Veeam products…

First up: VMware

I don’t often dedicate a blog post to a particular security vulnerability, but since it has scored a perfect 10 CVE rating, it’s important to be aware ASAP.

VMware have identified multiple products that utilise the Apache technology that are vulnerable to the Log4j vulnerability.

What is this “Log4j” vulnerability?

A Remote Code Execution (RCE) has been discovered in Apache’s Log4j Java Library. It is possible to insert maliciously crafted strings into fields that will be logged, which then leverages the “message lookup substitution” function of Log4j to execute code. This can be used to deploy and execute payloads, or execute commands at a heightened privilege level.

This is trivial to reproduce now the vulnerability has been confirmed to exist, hence the high score. This vulnerability isn’t exclusive to VMware.

What can I do?

Firstly, keep an eye on this VMware page for the latest updates and patch your systems as updates become available. It’s also a good idea to firewall your systems to prevent unauthorised access to limit any attack footprint. But restricting the footprint is of no substitute for a patch.

Finally, if you’re one of those people living on the edge with an externally accessible vCenter, odds are good you’ve already been compromised, get it off the internet now and check!

Second, What about Veeam?

I posted on the Veeam R&D forum this morning regarding Veeam’s vulnerability status regarding this, and thankfully it appears Apache isn’t used by any Veeam product, however the Veeam security team are still investigating.

I’ll cross-post any important updates but you can see the thread yourself here.

Hopefully Veeam won’t be impacted by this one as it’s honestly one of the scarier vulnerabilities I’ve ever seen due to how widespread this is.

Finally, a shout-out to @regnor as he was going to post about this himself if I hadn’t already! More eyes on these topics is always a good thing and I’m sure he’ll follow up with any insights that I’ve missed!

—UPDATE—

Veeam have confirmed via the R&D forum and via a KB that none of their products are impacted (thanks @Mildur )

https://www.veeam.com/kb4254

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BertrandFR
Influencer
516 comments
2 years ago
13 December 2021

it’s making lots of noises since friday for us, a poc was published on github in April (chinese language)

https://github.com/nice0e3/log4j_POC

French Cybersecurity Agency are observing attacks in honeypot infrastructure from Tor too.

Anyway for the veeam part, the answer from Gostev is comfortable:

Veeam R&D Forums Digest - THE WORD FROM GOSTEV

If you're using any software running on Apache and Java, be aware of this critical zero-day vulnerability. Log4j is a ubiquitous logging tool included in almost every Java application, meaning this vulnerability affects literally millions of servers. You can use software dependencies scanner like Syft to determine whether any of your Java apps use an affected version of Log4j. As for Veeam products, while I still need to get the official confirmation from our security team, it's unlikely we're affected because as far as I know we don't use Java in principle. Plus, as it comes to web servers, we're married to Microsoft IIS for our Windows-based apps (VBR/ONE/VSPC) and to nginx for Linux-based (Veeam Backup for AWS/Azure/GCP). The only place I'm aware that uses some Apache components is our SureBackup helper appliance, but that one certainly should not have any traces of Java.

Userlevel 7

+13

vNote42
Veeam Vanguard
1246 comments
2 years ago
13 December 2021

WOW, this issue will have unimaginable effects! For example Apache and Java can suffer from this issue! So many parts of the internet will be affected!

Userlevel 3

LostInEther
Comes here often
11 comments
2 years ago
15 December 2021

Red Hat products not affected:
https://access.redhat.com/security/vulnerabilities/RHSB-2021-009

Userlevel 7

+20

MicoolPaul
Author
Veeam Legend, Veeam Vanguard
2210 comments
2 years ago
18 December 2021

Unfortunately, there’s a new second CVE that’s need a new patch.

https://nvd.nist.gov/vuln/detail/CVE-2021-45046

Yes, log4j 2.16.0 is needed now. And who knows if this is the last issue :sunglasses:

Unfortunately this is getting worse. At first there was concern this would result in Denial of Service attacks, now the CVE severity is expected to be increased from 3.7 to around 9 as limited Remote Code Execution (RCE) has been discovered.