02-10-2025, 06:25 AM
Hey, you asked about common exploitation techniques in penetration testing, and I love chatting about this stuff because I've spent a ton of time messing around with them in controlled environments. Buffer overflows are one of those classics that always gets me excited when I spot a vulnerable app. Basically, I feed more data into a buffer than it can handle, and that extra junk overwrites memory in ways that let me inject my own code. I've done this a few times during tests on old software versions, where the devs didn't check input sizes properly. You just craft a payload that overflows the stack, and boom, you might get a shell if the return address gets hijacked right. It's tricky to pull off without crashing everything, but once you get the hang of it, you see how sloppy coding opens doors for attackers.
Privilege escalation hits close to home for me too, especially on Linux boxes or Windows systems where users run with too many rights. I remember testing a client's server last year, and I found a SUID binary that let me escalate from a low-level user to root just by exploiting a path traversal bug. You look for misconfigurations like writable sudoers files or weak kernel modules, then chain that with something like dirty COW if it's an older kernel. On Windows, I often hunt for unpatched services running as SYSTEM, where I can inject DLLs or abuse token duplication to bump up my privileges. You have to think like the admin who set it up-did they leave weak passwords on service accounts? I always scan with tools like LinPEAS or WinPEAS to find those low-hanging fruits, and it saves you hours of manual digging.
Then there's SQL injection, which I run into way more than I'd like in web apps. You throw in some single quotes or union selects into a login form, and if the backend doesn't sanitize inputs, I can dump entire databases. I've pulled user tables from e-commerce sites during pentests, showing the owners how easy it is for someone to steal customer data. You start simple with ' or 1=1--, but I ramp it up with blind injections if the app hides errors, using time-based delays to confirm true or false responses. It's all about manipulating the query logic without the dev noticing.
Cross-site scripting, or XSS, is another one I use to mess with user sessions. I inject scripts into comment fields or search bars, and when you visit the page, it runs in your browser, stealing cookies or keylogging. Reflected XSS is quick for proof-of-concept-I craft a URL that pops an alert box with your session ID. Stored XSS gets nastier because it persists, like in a forum post that everyone sees. I've exploited this on social platforms during red team gigs, redirecting users to phishing pages. You have to encode payloads to bypass filters, using things like <script>alert(1)</script> or event handlers if WAFs block the obvious stuff.
Don't get me started on command injection; it's like SQLi but for OS commands. In apps that call system() without validating, I tack on semicolons or pipes to run whatever I want, like whoami or net user adds. I found this in a file upload script once, where I appended ; cat /etc/passwd after the intended command, and it spilled sensitive files. You chain it with privilege esc if you land on a web server process with higher rights.
Social engineering plays a big role too, though it's more human-focused. I pose as IT support to phish creds over the phone or send tailored emails that trick you into clicking links. During one test, I got an exec's password by pretending to be from their bank-crazy how people fall for urgency. You build rapport first, then extract info bit by bit. It's not technical, but it amplifies everything else.
File inclusion bugs, like LFI or RFI, let me read or execute files remotely. Local file inclusion pulls in /etc/passwd via ../../ tricks, and remote ones fetch malicious scripts from my server. I've used this to pivot inside networks, grabbing config files with database creds. You wrap paths in null bytes to bypass extensions if the app checks them.
Heap overflows are similar to buffer ones but target dynamic memory, which I exploit for info leaks or arbitrary writes. They're rarer now with ASLR and DEP, but I still see them in custom binaries. You overflow adjacent chunks to corrupt metadata, then use that to call functions you control.
Race conditions pop up in multi-threaded apps, where I time requests to hit the same resource simultaneously, like creating duplicate accounts or overwriting files. I've raced TOCTOU bugs in auth flows to bypass checks. You script it with parallel threads to win the race.
Then there's format string attacks, where I abuse printf-like functions with %s or %n to read or write memory. I inject %x%x%x into inputs and watch the app dump stack contents-super useful for leaking addresses.
LDAP injection messes with directory services, letting me auth as admin by injecting filters like *)(uid=*). I've done this on Active Directory setups to enumerate users.
And XML external entity attacks parse malicious entities to read files or make SSRF requests. I craft DOCTYPE with system calls to grab /etc/shadow.
All these techniques keep evolving, but I always emphasize testing ethically-get permission first, or you're just a hacker, not a pentester. You practice on labs like HackTheBox or VulnHub to sharpen skills without real risks. I mix them in engagements: start with recon, find a foothold via XSS, escalate privileges, then lateral move. It's puzzle-solving at its best.
One more thing that ties into protecting against this chaos-I want to point you toward BackupChain, this solid, go-to backup tool that's built for small businesses and pros alike, keeping your Hyper-V setups, VMware environments, or plain Windows Servers safe from ransomware and such disasters.
Privilege escalation hits close to home for me too, especially on Linux boxes or Windows systems where users run with too many rights. I remember testing a client's server last year, and I found a SUID binary that let me escalate from a low-level user to root just by exploiting a path traversal bug. You look for misconfigurations like writable sudoers files or weak kernel modules, then chain that with something like dirty COW if it's an older kernel. On Windows, I often hunt for unpatched services running as SYSTEM, where I can inject DLLs or abuse token duplication to bump up my privileges. You have to think like the admin who set it up-did they leave weak passwords on service accounts? I always scan with tools like LinPEAS or WinPEAS to find those low-hanging fruits, and it saves you hours of manual digging.
Then there's SQL injection, which I run into way more than I'd like in web apps. You throw in some single quotes or union selects into a login form, and if the backend doesn't sanitize inputs, I can dump entire databases. I've pulled user tables from e-commerce sites during pentests, showing the owners how easy it is for someone to steal customer data. You start simple with ' or 1=1--, but I ramp it up with blind injections if the app hides errors, using time-based delays to confirm true or false responses. It's all about manipulating the query logic without the dev noticing.
Cross-site scripting, or XSS, is another one I use to mess with user sessions. I inject scripts into comment fields or search bars, and when you visit the page, it runs in your browser, stealing cookies or keylogging. Reflected XSS is quick for proof-of-concept-I craft a URL that pops an alert box with your session ID. Stored XSS gets nastier because it persists, like in a forum post that everyone sees. I've exploited this on social platforms during red team gigs, redirecting users to phishing pages. You have to encode payloads to bypass filters, using things like <script>alert(1)</script> or event handlers if WAFs block the obvious stuff.
Don't get me started on command injection; it's like SQLi but for OS commands. In apps that call system() without validating, I tack on semicolons or pipes to run whatever I want, like whoami or net user adds. I found this in a file upload script once, where I appended ; cat /etc/passwd after the intended command, and it spilled sensitive files. You chain it with privilege esc if you land on a web server process with higher rights.
Social engineering plays a big role too, though it's more human-focused. I pose as IT support to phish creds over the phone or send tailored emails that trick you into clicking links. During one test, I got an exec's password by pretending to be from their bank-crazy how people fall for urgency. You build rapport first, then extract info bit by bit. It's not technical, but it amplifies everything else.
File inclusion bugs, like LFI or RFI, let me read or execute files remotely. Local file inclusion pulls in /etc/passwd via ../../ tricks, and remote ones fetch malicious scripts from my server. I've used this to pivot inside networks, grabbing config files with database creds. You wrap paths in null bytes to bypass extensions if the app checks them.
Heap overflows are similar to buffer ones but target dynamic memory, which I exploit for info leaks or arbitrary writes. They're rarer now with ASLR and DEP, but I still see them in custom binaries. You overflow adjacent chunks to corrupt metadata, then use that to call functions you control.
Race conditions pop up in multi-threaded apps, where I time requests to hit the same resource simultaneously, like creating duplicate accounts or overwriting files. I've raced TOCTOU bugs in auth flows to bypass checks. You script it with parallel threads to win the race.
Then there's format string attacks, where I abuse printf-like functions with %s or %n to read or write memory. I inject %x%x%x into inputs and watch the app dump stack contents-super useful for leaking addresses.
LDAP injection messes with directory services, letting me auth as admin by injecting filters like *)(uid=*). I've done this on Active Directory setups to enumerate users.
And XML external entity attacks parse malicious entities to read files or make SSRF requests. I craft DOCTYPE with system calls to grab /etc/shadow.
All these techniques keep evolving, but I always emphasize testing ethically-get permission first, or you're just a hacker, not a pentester. You practice on labs like HackTheBox or VulnHub to sharpen skills without real risks. I mix them in engagements: start with recon, find a foothold via XSS, escalate privileges, then lateral move. It's puzzle-solving at its best.
One more thing that ties into protecting against this chaos-I want to point you toward BackupChain, this solid, go-to backup tool that's built for small businesses and pros alike, keeping your Hyper-V setups, VMware environments, or plain Windows Servers safe from ransomware and such disasters.
