Author Archives: Alexander Leonov

About Alexander Leonov

Hi! My name is Alexander and I am a Vulnerability Management specialist. You can read more about me here. Currently, the best way to follow me is my Telegram channel @avleonovcom. I update it more often than this site. If you haven't used Telegram yet, give it a try. It's great. You can discuss my posts or ask questions at @avleonovchat. А всех русскоязычных я приглашаю в ещё один телеграмм канал @avleonovrus, первым делом теперь пишу туда.

Microsoft Patch Tuesday May 2023: Microsoft Edge, BlackLotus Secure Boot SFB, OLE RCE, Win32k EoP, NFS RCE, PGM RCE, LDAP RCE, SharePoint RCE

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Hello everyone! This episode will be about Microsoft Patch Tuesday for May 2023, including vulnerabilities that were added between April and May Patch Tuesdays.

Alternative video link (for Russia): https://vk.com/video-149273431_456239126

As usual, I use my open source Vulristics project to analyse and prioritize vulnerabilities. I took the comments about the vulnerabilities from the Qualys, Tenable, Rapid7, ZDI Patch Tuesday reviews.

It’s been a long time since we’ve had such tiny Patch Tuesday. 57 CVEs, including CVEs appeared during the month. And only 38 without them! 😄

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Microsoft Patch Tuesday April 2023: CLFS EoP, Word RCE, MSMQ QueueJumper RCE, PCL6, DNS, DHCP

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Hello everyone! This episode will be about Microsoft Patch Tuesday for April 2023, including vulnerabilities that were added between March and April Patch Tuesdays.

Alternative video link (for Russia): https://vk.com/video-149273431_456239123

As usual, I use my open source Vulristics project to analyse and prioritize vulnerabilities. I took the comments about the vulnerabilities from the Qualys, Tenable, Rapid7, ZDI Patch Tuesday reviews. And this is the first Patch Tuesday report since I added EPSS support to Vulristics. 😉

Compared to March, Microsoft Patch Tuesday for April 2023 is kind of weak. 🙄

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Vulristics News: EPSS v3 Support, Integration into Cloud Advisor

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Hello everyone! This episode will focus on the news from my open source Vulristics project for vulnerability analysis and prioritization.

Alternative video link (for Russia): https://vk.com/video-149273431_456239122

EPSS v3

The third iteration of the Exploit Prediction Scoring System (EPSS) was released in March. It is stated that EPSS has become 82% better. There is a pretty cool and detailed article about the changes. For example, EPSS Team began to analyze not 16 parameters of vulnerabilities, but 1164. I have a suspicion that most of these properties are vendor labels, as in the table.

But trying to figure out how it actually works is not very promising. After all, this is the output of some neural network. So there is no algorithm there. In terms of complexity and incomprehensibility, this is already similar to Tenable VPR. But the fact that EPSS is available for free redeems everything. 😇 By the way, the article mentions Tenable VPR and other commercial scores and criticizes them for their proprietary nature, public inaccessibility, and the fact that these scores are partly based on expert opinion, and not just on data.

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Microsoft Patch Tuesday March 2023: Outlook EoP, MOTW Bypass, Excel DoS, HTTP/3 RCE, ICMP RCE, RPC RCE

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Hello everyone! This episode will be about Microsoft Patch Tuesday for March 2023, including vulnerabilities that were added between February and March Patch Tuesdays.

Alternative video link (for Russia): https://vk.com/video-149273431_456239119

As usual, I use my open source Vulristics project to analyse and prioritize vulnerabilities. I took the comments about the vulnerabilities from the Qualys, Tenable, Rapid7, ZDI Patch Tuesday reviews.

Microsoft Patch Tuesday for March 2023 was quite refreshing. 😈

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Microsoft Patch Tuesday February 2023: Win Graphics RCE, Edge RCE, Publisher SFB, CLFS EoP, Exchange RCEs, Word RCE, HoloLens1

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Hello everyone! This episode will be about Microsoft Patch Tuesday for February 2023, including vulnerabilities that were added between January and February Patch Tuesdays.

Alternative video link (for Russia): https://vk.com/video-149273431_456239118

This month I decided to change the format a bit. Now I share my impression of Microsoft Patch Tuesday on the same Patch Tuesday day in my main telegram channel avleonovcom and my second russian telegram channel avleonovrus. You can also find a draft of the Vulristics report there. So please subscribe. And the full blog post/video is published with a delay. And, in fact, this is it.

As usual, I use my open source Vulristics project to analyse and prioritize vulnerabilities. I took the comments about the vulnerabilities from the Qualys, Tenable, Rapid7, ZDI Patch Tuesday reviews.

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Microsoft Patch Tuesday January 2023: ALPC EoP, Win Backup EoP, LocalPotato, Exchange, Remote RCEs

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Hello everyone! This episode will be about Microsoft Patch Tuesday for January 2023, including vulnerabilities that were added between December and January Patch Tuesdays.

Alternative video link (for Russia): https://vk.com/video-149273431_456239115

As usual, I use my open source Vulristics project to analyse and prioritize vulnerabilities. I took the comments about the vulnerabilities from the Qualys, Nessus, Rapid7 and ZDI Patch Tuesday reviews.

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How Debian OVAL content is structured

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Hello everyone! As we saw in the last episode, the results of vulnerability detection for one host produced by two different APIs can vary greatly. Therefore, in order to find out the truth, it is necessary to understand what vulnerability data is provided by the Linux distribution vendor and how this data is structured.

Alternative video link (for Russia): https://vk.com/video-149273431_456239114

Why is it important to do this? Because using data from a Linux distribution vendor, we can ask vulnerability detection API vendors questions: why are you detecting in a different way than described in this data? And then we will understand what caused the difference. And we will either adjust the API for vulnerability detection, or we will adjust the content of the Linux distribution vendor. Either way, it will be a success! In any case, the transparency of the vulnerability detection process will increase.

Last time we looked at vulnerabilities for Debian host and Debian Docker base image. So let’s continue with Debian. In particular, with the official Debian OVAL (Open Vulnerability and Assessment Language) content.

Debian OVAL content can be downloaded from the https://debian.org/security/oval/ website. For Debian 11.6 it will be https://debian.org/security/oval/oval-definitions-bullseye.xml (~48M).

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