A buffer overflow, or buffer overrun, is an anomaly where a program, while writing data to a buffer, overruns the buffer's boundary and overwrites adjacent memory.

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Are Sun/Oracle's SPARC processors invulnerable to buffer overrun exploits?

We all use Intel architectures these days, in small part because Oracle has totally dropped the ball regarding SPARC CPU development. But with so many now saying that protection against viruses is ...
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When is memory allocation/layout deterministic?

I'm trying to learn about buffer overflow attacks, both on the stack and on the heap. However, I'm confused about when it's possible to determine the address of the buffer. The classic "Smashing the ...
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Long character sequence in first string of HTTP GET request breaks the web service's HTTP response. Buffer overflow?

During my current security audit test I've stumbled on something I can't possibly comprehend. The behavior exhibits signs of a buffer overflow in the target or in some intermidiate service (HTTP ...
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22 views

Getting a DEP exception when trying to call SetProcessDEPException(false)

I'm demonstrating an exploit for an old app. On Windows XP SP3 32bit (EN), the address of SetProcessDEPPolicy() is usually 0x7C8622A4. I have that version of Windows (in English as well) and I've ...
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Stack buffer overflow: Is compiler changing variables order, preventing me to overwrite EIP properly?

I am learning about stack buffer overflow. A little info about my target: A x86 little endian intel-based computer, with a target compiled with TCC Compiler with no protections of any kind running on ...
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18 views

Execute form environmental variable while stack is not executable

Strange thing happened. I created EGG=NOPs + shellcode. Then i get the address of EGG; I made buffer overflow and jumped to it and get the shell(address of shell is the second parametr). How is this ...
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How to gain root privilege after injecting code using a buffer overflow vulnerability?

Once the attacker finds an exploitable vulnerability in a user program, e.g., buffer overflow. Assume his goal is to gain root privilege and typical countermeasures are not present in the system ...
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120 views

Are buffer overflows on websites stoppable?

Recently, I was at the bookstore checking out books on computers. I found an interesting book on various types of hacks and how to stop them on your servers. One that caught my eye was the "buffer ...
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100 views

Program exiting after executing int 0x80 instruction when running shellcode

In school I was given an assignment to perform a buffer overflow, which would execute some shellcode and open a new shell. After a bit of fiddling the buffer overflow succeeded, and when I ran the ...
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868 views

Exploiting buffer overflow leads to segfault

I am trying to exploit simple stack overflow vulnerability. I have a basic code in c: #include <cstring> int main( int argc, char** argv ) { char buffer[500]; strcpy(buffer, ...
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63 views

Buffer overflow without using environment variables [closed]

I was trying to overflow buffers and I was wondering , Is there anyway to do a buffer overflows without using environment variables ?
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95 views

Bypass Full ASLR+DEP exploit mitigation

Let's assume that a vulnerabled process is set up with an ASLR and DEP against all the imported modules used in this process and there is no way to find a module that is aslr free.. More over, the ...
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In buffer overflow exploit, 0x20 (space character) not appearing in memory and is replaced by null

The situation: I'm currently working on shellcode (I modified the assembly code from Project Shellcode) that runs "cmd.exe /c calc.exe". The shellcode itself works fine. However, when I use the ...
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525 views

Buffer overflow - terminator canaries

I am reading an article on buffer overflow protection here. For terminator canaries, I follow the part that if a terminator like a zero is used for a canary, the attacker would have a terminator in ...
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3answers
229 views

C++ memset() memory overflow

I am new to C++. Can any C++ expert tell me would this causing buffer overflow? Sample Code: MyObject op; memset(&op, 0, sizeof(MyObject)); On my view it is ok to be this since the limit is ...
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1answer
77 views

Are stack buffer overflows even possible in this instance?

Let's say there is a C program that simply takes a string argv[1] and uses sprintf to copy it in a finite buffer. Classic stack buffer overflow. Let's even say the program is more complicated, ...
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512 views

Drive-by downlad VS buffer and stack overflow attacks

Today malware is mainly spread thanks to vulnerabilities exploited in browsers and their plugins. The attackers use JavaScript to target those vulnerabilities. Two examples of such attacks are ...
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110 views

Does glibc use canary checking to prevent heap buffer overflow?

Since canary is used by gcc to prevent stack overflow (e.g. -fstack-protector), I am wondering whether glibc uses canary-based approach to defend heap buffer overflow? For example, this paper proposes ...
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4answers
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Adding 65K buffer to protect from buffer overflows?

If you had a very complex and important function in C that you wanted to protect, would it be worth it to put a 65K buffer at the top of the stack to protect from buffer overflows? You would put your ...
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2answers
108 views

Possible to use buffer overflow on DLL-injected code?

Is it possible to apply buffer overflow on code that was injected using DLL injection? For instance, if I inject a function foo() into the process, is it possible to call foo() using buffer overflow? ...
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90 views

Is OpenSSL 0.9.8h affected by CVE-2014-0195?

I have spent time on finding out if OpenSSL 098h is affected by the CVE-2014-0195 ..but it seems I will have to understand the entire file d1_both.c to answer this question. 1) Preliminary look at ...
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2answers
223 views

Heap canaries, to protect function pointers in heap objects

I'm wondering if anyone has previously proposed, evaluated, or deployed the following measure to harden systems against heap-based buffer overruns: basically, stack canaries, but applied before ...
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2answers
242 views

Heap spray against 64-bit processes - possible?

Are heap spray exploits possible, if the process we're attacking is a 64-bit process? Naively, it seems like the 64-bit address makes it difficult to mount a heap spray: to fill all (or a significant ...
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169 views

Why are countermeasures against control-flow hijacking attacks mostly implemented in software?

I wonder why countermeasures against code-injection and control-flow hijacking attacks (e.g. stack-based buffer overflows and heap-based buffer overflows) are mostly implemented in software. Examples ...
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226 views

Information disclosure attack, using a heap overflow

A typical strategy for defeating ASLR is to find both a buffer overflow bug and an information disclosure bug. But when attacking servers that are automatically restarted whenever they crash/die, is ...
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153 views

Buffer Overflow Exploit Shellcode for Windows

Using a buffer overflow, I have been able to override return addresses. But the problem is that Windows addresses contain zeros at the beginning (e.g. 0x00401020). As a result, the objdump of any C ...
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70 views

libraries alternative to gcc stack-protector / fortity source feature on linux

is there external library/approach/whatever to add canary protection (stack-protector equivalent) extra buffer boundary check (fortity source equivalent) on a C software without using glibc / ...
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90 views

Does ASLR protect against a buffer overflow within a struct?

Assume a simple struct: struct test { char variable[4]; char variable2; } If I write something like variable[4] = '\0' there is a buffer overflow which modifies variable2. Does ASLR prevent ...
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89 views

3 byte address of system call and exit call

i am trying to exploit a buffer overflow vulnerability in ubuntu (kernel version 3.0.0-12 generic i686) by using the method return to libc and the stack is not exploiting ? By while exploiting i ...
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2answers
70 views

8 extra bytes in stack

i am new to buffer overflow and learning from securitytube.net website but in 7th video i got stucked Buffer Overflow Primer Part 7 (Exploiting A Program Demo) In this when the value of egg is passed ...
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123 views

Exploiting buffer overflow

When I download a copy of a vulnerable program and try to exploit it by buffer overflow (any internal function calling as a payload), it works. However, when I made a same type of vulnerable program ...
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1answer
87 views

Examples of software web clients (web browsers, IM clients, etc) written in “secure” / managed languages

After reading this article ("Everything is broken" by Quinn Norton) I was about to ask a question similar to this one (Why are security-crucial software written in unsafe languages?)... but actually I ...
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217 views

Defend against Blind ROP

At IEEE Security & Privacy, the blind return-oriented programming attack (blind ROP) was just introduced. In some sense, this is just another variation on ROP attacks -- but the blind ROP attack ...
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273 views

In return to libc how do you know the address of system() in a remote machine?

I have the following scienarion: a vulnerable program running in a server and can be accessed using netcat I have a copy of that program locally and I can exploit it locally using ROP: ./vuln ...
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159 views

What should you do if you cannot spawn a shell in a buffer overflow attack?

I have successfully exploited a program using ret2libc but I am running into a problem. Whenever I feed system() with /bin/sh I have nothing in return the program silently exit. However, if I feed ...
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Stack-based buffer overflow the program is interpreting the shellcode on its own

I'm beginner in exploits. So I had type simple program in C #include <stdio.h> void func(){ printf("asd"); } main(){ char buf[100]; scanf("%s", &buf); } My goal is to run the ...
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2answers
141 views

Why is it so difficult to protect an application against buffer overflows?

For example, buffer overflow vulnerabilities in Flash are often discovered. Shouldn't a proper verification of all function parameters in Flash source code be enough to protect against buffer ...
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165 views

Fomat String vulnerability used to display data outside the function stack frame?

if we run the following code using the input "hi", the output will simply be "hi" main(int argc, char **argv) { char *secret = "This is a secret 1\n"; char *secret2 = "This is ...
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Would the Heartbleed bug have been prevented if OpenSSL was written in Go/D/Vala?

IIUC the Heartbleed vulnerability happens due to a bug in the C source code of OpenSSL, by performing a memcpy() from a buffer that is too short. I'm wondering if the bug would have been prevented ...
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Should I worry about this UAC bypass exploit for Windows 7?

It appears that there is an exploit out there that allegedly allows you to bypass the UAC on Windows 7 computers and gain administrator access. I was wondering if this exploit is still a dangerous ...
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How to explain buffer overflow to a layman

Every once in a while (when I think out loud and people overhear me) I am forced to explain what a buffer overflow is. Because I can't really think of a good metaphor, I end up spending about 10 ...
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725 views

buffer overflow in python script

I am developing a script to perform an a buffer overflow for an assignment in school. However, I am stuck at a point where my payload works injected through the commandline, but not injected through ...
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1answer
282 views

Can this code be expoited using Buffer Overflow?

I have a piece of code which contains an obvious buffer overflow at strcpy(buf, x) since it doesn't check if buf is large enough to fit the string x. I'm wondering how to actually exploit this bug. ...
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510 views

Python exploit question?

Can someone please explain how and why this struct.pack code is used in the below exploit? I'm trying to understand how it triggers the vulnerability. I understand the buffer overflow aspect, I'm ...
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1answer
254 views

EIP pointer is overwritten but EBP remains intact

I was trying out a simple stack buffer overflow exploit by creating a malicious crash.m3u file. as you can see the EIP pointer is overwritten by "A" but EBP hasn't changed. isn't EBP supposed to get ...
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143 views

Why does this buffer overflow have payload &system-&exit-&BINSH

I'm following a tutorial to write a simple buffer overflow. I have (basic) knowledge of assembly, and the stack. I've written a stack based buffer overflow before and understood it. The program I'm ...
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Inversed Data Direction on the Stack

As I remember from my micro controller course, the stack is at the end of the memory, while at the begin are some interrupt pointers, program code and later data. Since the stack is at the end of the ...
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Examples of images causing buffer overflows? [closed]

I remember reading a news article of an incident where a hacker was able to use an image to infect thousands (maybe millions?) of computers. Can anyone provide links to such news articles? I couldn't ...
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199 views

Using buffer overflow on word with macro injection

I know how a buffer overflow works on a local network against an application running on a TCP port, assuming it doesn't drop the connection, but I would like some advice on an "exploit" I would like ...
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Is there any security concerns for CGI scripts written in pure bash?

I'm working on a project that would use bash and fastcgi to create a psudo-CMS, is there any kind of security concerns to watch out for (ie buffer overflows, and the like)?