CVSS

2 Articles

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

October 3, 2025 by No 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” →