Exchange 2016
Solve Exchange 2019 SMTP error by quickly updating your DNS.
In one of my lab servers, I was busy working on a project and email would just not send. I kept on getting the error below from the consoles output: Error with SMTP server... (451, b'4.7.0 Temporary server error. Please try again later. PRX2') This error is generic...
Secure Exchange 2019 OWA with a Google Captcha option.
In one of my recent blog posts, we covered brute forcing of the OWA page in Exchange 2019, this also applies to Exchange 2016 and Exchange 2013. If an attacker successfully gains access, they might access an account that has elevated privileges or given enough time,...
Exchange 2019:- ProxyToken Exploit
In three of my previous blog posts, we looked at exploiting unpatched/vulnerable Exchange servers with "ProxyLogon", "ProxyShell" and "ProxyNotShell". As the exploit lists keep growing, we will look at the "ProxyToken" exploit. One of my many Exchange 2019 lab servers...
Exchange 2019:- ECP_DLP_Policy Exploit
I have been covering some of the exploits in Exchange Server in a few of my blog posts and wanted to highlight the fact that I tested another one which allowed me to get a shell on the Exchange Server. Metasploit has a module for the above exploit which worked against...
Exchange 2019:- ProxyNotShell Exploit
In two of my previous blog posts, we looked at exploiting unpatched/vulnerable Exchange servers with "ProxyLogon" and "ProxyShell". As the exploit lists keep growing, we will look at the "ProxyNotShell" exploit. One of my many Exchange 2019 lab servers was running...
Exchange 2019:- ProxyShell Exploit
In my previous blog post we looked at the Proxy Logon Exploit where several CVE's could be used to exploit an Exchange Server. In this article we will look at another exploit called "ProxyShell". The CVE for this vulnerability is "CVE-2021-34473". Let's head over to...
Exchange 2019:- ProxyLogon Exploit
Many of us know the HAFNIUM attacks that took place a little while ago and many Exchange servers were compromised. The sad part is that many Exchange Servers are still unpatched and vulnerable to attack, maybe not to the CVE's listed below but to others as well. One...
Exchange 2019:- Brute forcing OWA to gain access to user accounts
We all know that end users hate complex passwords and having to change passwords often leads them to use the same password but add a number or character at the end of it. Password complexity is just one of the problems. The next problem is information disclosure such...
Information disclosure with NTLM Authentication in Exchange Server
Performing some tests against my lab Exchange servers, I noticed that Shodan.io revealed information. Take note that attackers also use Shodan.io when enumerating targets. After digging further with NMAP and some scripts, it became more apparent that internal...
Exchange 2016:- Move request failures are not always due to space/back pressure but sometimes misconfigurations
As an IT Admin, mailbox migrations are a constant thing. Moving users to new databases because you have a new database or you trying clean up and old one with few users, or simply moving to Microsoft 365, there are times when things error out. Errors are not always...