CVSS

4 Articles

This Week In Security: F5, SonicWall, And The End Of Windows 10

October 17, 2025 by 12 Comments

F5 is unintentionally dabbling in releasing the source code behind their BIG-IP networking gear, announcing this week that an unknown threat actor had access to their internal vulnerability and code tracking systems. This security breach was discovered on August 9th, and in the time since, F5 has engaged with CrowdStrike, Mandiant, and NCC Group to review what happened.

So far it appears that the worst result is access to unreleased vulnerabilities in the F5 knowledge management system. This means that any unpatched vulnerabilities were effectively 0-days, though the latest set of patches for the BIG-IP system has fixed those flaws. There aren’t any reports of those vulnerabilities being exploited in the wild, and F5 has stated that none of the leaked vulnerabilities were critical or allowed for remote exploitation.

Slightly more worrying is that this access included the product development environment. The problem there isn’t particularly the leak of the source code — one of the covered projects is NGINX, which is already open source software. The real danger is that changes could have been surreptitiously added to those codebases. The fact that NGINX is Open Source goes a long way to alleviate that danger, and when combined with the security built into tools like git, it seems very unlikely that malicious code could be sneaked into the NGINX public code base. A thorough review of the rest of the F5 codebases has similarly come up negative, and so far it looks like the supply-chain bullet has been dodged. Continue reading “This Week In Security: F5, SonicWall, And The End Of Windows 10” →

This Week In Security: ID Breaches, Code Smell, And Poetic Flows

October 10, 2025 by 10 Comments

Discord had a data breach back on September 20th, via an outsourced support contractor. It seems it was a Zendesk instance that was accessed for 58 hours through a compromised contractor user account. There have been numbers thrown around from groups claiming to be behind the breach, like 1.6 Terabytes of data downloaded, 5.5 million user affected, and 2.1 million photos of IDs.

Discord has pushed back on those numbers, stating that it’s about 70,000 IDs that were leaked, with no comments on the other claims. To their credit, Discord has steadfastly refused to pay any ransom. There’s an interesting question here: why were Discord users’ government issued IDs on record with their accounts?

The answer is fairly simple: legal compliance. Governments around the world are beginning to require age verification from users. This often takes the form of a scan of valid ID, or even taking a picture of the user while holding the ID. There are many arguments about whether this is a good or bad development for the web, but it looks like ID age verification is going to be around for a while, and it’ll make data breaches more serious.

In similar news, Salesforce has announced that they won’t be paying any ransoms to the group behind the compromise of 39 different Salesforce customers. This campaign was performed by calling companies that use the Salesforce platform, and convincing the target to install a malicious app inside their Saleforce instance. Continue reading “This Week In Security: ID Breaches, Code Smell, And Poetic Flows” →

This Week In Security: CVSS 0, Chwoot, And Not In The Threat Model

October 3, 2025 by 4 Comments

This week a reader sent me a story about a CVE in Notepad++, and something isn’t quite right. The story is a DLL hijack, a technique where a legitimate program’s Dynamic Link Library (DLL) is replaced with a malicious DLL. This can be used for very stealthy persistence as well as escalation of privilege. This one was assigned CVE-2025-56383, and given a CVSS score of 8.4.

The problem? Notepad++ doesn’t run as a privileged user, and the install defaults to the right permissions for the folder where the “vulnerable” DLL is installed. Or as pointed out in a GitHub issue on the Proof of Concept (PoC) code, why not just hijack the notepad++ executable?

This is key when evaluating a vulnerability write-up. What exactly is the write-up claiming? And what security boundary is actually being broken? The Common Weakness Enumeration (CWE) list can be useful here. This vulnerability is classified as CWE-427, an uncontrolled search path element — which isn’t actually what the vulnerability claims, and that’s another clue that something is amiss here. In reality this “vulnerability” applies to every application that uses a DLL: a CVSS 0.

Continue reading “This Week In Security: CVSS 0, Chwoot, And Not In The Threat Model” →

This Week In Security: CVSS 4, OAuth, And ActiveMQ

November 3, 2023 by 4 Comments

We’ve talked a few times here about the issues with the CVSS system. We’ve seen CVE farming, where a moderate issue, or even a non-issue, gets assigned a ridiculously high CVSS score. There are times a minor problem in a library is a major problem in certain use cases, and not an issue at all in others. And with some of those issues in mind, let’s take a look at the fourth version of the Common Vulnerability Scoring System.

One of the first tweaks to cover is the de-emphasis of the base score. Version 3.1 did have optional metrics that were intended to temper the base score, but this revision has beefed that idea up with Threat Metrics, Environmental Metrics, and Supplemental Metrics. These are an attempt to measure how likely it is that an exploit will actually be used. The various combinations have been given names. Where CVSS-B is just the base metric, CVSS-BT is the base and threat scores together. CVSS-BE is the mix of base and environmental metrics, and CVSS-BTE is the combination of all three.

Another new feature is multiple scores for a given vulnerability. A problem in a library is first considered in a worst-case scenario, and the initial base score is published with those caveats made clear. And then for each downstream program that uses that library, a new base score should be calculated to reflect the reality of that case. Continue reading “This Week In Security: CVSS 4, OAuth, And ActiveMQ” →