Buffer Overflow
A buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions.
How It Works
A buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions. This overwrites whatever data or code exists there, corrupting program state and potentially giving attackers control over execution flow.
Stack-based overflows are the most common variant. When a function allocates a fixed-size buffer on the stack and then copies user-controlled input without proper bounds checking, attackers can overflow past the buffer to overwrite the function's return address. When the function completes, instead of returning to legitimate code, execution jumps to attacker-specified memory containing malicious shellcode. Heap-based overflows work differently—they corrupt heap metadata like chunk size fields or free list pointers, leading to arbitrary memory writes when the allocator processes the corrupted structures.
Modern exploitation bypasses defensive mechanisms through techniques like Return-Oriented Programming (ROP), which chains together existing code snippets to avoid non-executable memory protections. Attackers may also use heap spraying to reliably position shellcode at predictable addresses, defeating address randomization.
Impact
- Remote code execution — attacker gains ability to run arbitrary commands with the privileges of the vulnerable process
- Privilege escalation — exploiting kernel or setuid program overflows to gain root/SYSTEM access
- Denial of service — crashes and memory corruption that render systems unusable
- Information disclosure — reading sensitive data from adjacent memory regions that should be inaccessible
- Authentication bypass — overwriting security-critical variables like permission flags or user IDs
Real-World Examples
Fortinet FortiOS suffered a critical buffer overflow (CVE-2025-32756) that allowed unauthenticated remote attackers to execute code as root on firewalls and VPN gateways. Attackers actively exploited this to compromise enterprise network perimeters before patches were available.
The Slammer worm from 2003 exploited a stack overflow in Microsoft SQL Server, spreading to 75,000 hosts in ten minutes by sending a single malformed UDP packet that overwrote the return address with shellcode. No authentication was required.
OpenSSH historically contained a heap overflow in challenge-response authentication that allowed pre-authentication remote root compromise on Unix systems, demonstrating how memory corruption in privileged network services creates maximum impact scenarios.
Mitigation
- Memory-safe languages — Rust, Go, and modern managed languages prevent buffer overflows by design through automatic bounds checking
- Stack canaries — random values placed before return addresses that detect corruption before control transfer
- Address Space Layout Randomization (ASLR) — randomizes memory locations making exploitation less reliable
- Data Execution Prevention (DEP/NX) — marks memory regions as non-executable, preventing direct shellcode execution
- Bounds checking — validate input sizes before copying, use safe functions like
strncpyinstead ofstrcpy - Fuzzing and static analysis — automated testing to discover overflows before deployment
Recent CVEs (36782)
An exploitable uninitialized variable vulnerability which leads to a stack-based buffer overflow exists in Iceni Argus. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An integer overflow at an unserialize_uep memory allocation site would occur for vim before patch 8.0.0378, if it does not properly validate values for tree length when reading a corrupted undo file,. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
An integer overflow at a u_read_undo memory allocation site would occur for vim before patch 8.0.0377, if it does not properly validate values for tree length when reading a corrupted undo file,. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
JustSystems Ichitaro 2016 Trial contains a vulnerability that exists when trying to open a specially crafted PowerPoint file. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required. No vendor patch available.
When processing a record type of 0x3c from a Workbook stream from an Excel file (.xls), JustSystems Ichitaro Office trusts that the size is greater than zero, subtracts one from the length, and uses. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
When copying filedata into a buffer, JustSystems Ichitaro Office 2016 Trial will calculate two values to determine how much data to copy from the document. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
The demangle_template_value_parm and do_hpacc_template_literal functions in cplus-dem.c in libiberty allow remote attackers to cause a denial of service (out-of-bounds read and crash) via a crafted. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity.
Buffer overflow in the do_type function in cplus-dem.c in libiberty allows remote attackers to cause a denial of service (segmentation fault and crash) via a crafted binary. Rated medium severity (CVSS 4.4), this vulnerability is low attack complexity.
The d_print_comp function in cp-demangle.c in libiberty allows remote attackers to cause a denial of service (segmentation fault and crash) via a crafted binary, which triggers infinite recursion and. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. This Buffer Overflow vulnerability could allow attackers to corrupt memory to execute arbitrary code or crash the application.
Integer overflow in the string_appends function in cplus-dem.c in libiberty allows remote attackers to execute arbitrary code via a crafted executable, which triggers a buffer overflow. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
IBM Tivoli Storage Manager Server 7.1 could allow an authenticated user with TSM administrator privileges to cause a buffer overflow using a specially crafted SQL query and execute arbitrary code on. Rated high severity (CVSS 7.2), this vulnerability is remotely exploitable, low attack complexity.
An issue was discovered in tnef before 1.4.13. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. This Out-of-bounds Read vulnerability could allow attackers to read data from memory outside the intended buffer boundaries.
An issue was discovered in tnef before 1.4.13. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. This Out-of-bounds Read vulnerability could allow attackers to read data from memory outside the intended buffer boundaries.
An issue was discovered in tnef before 1.4.13. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. This Integer Overflow vulnerability could allow attackers to cause unexpected behavior through arithmetic overflow.
An issue was discovered in tnef before 1.4.13. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. This Out-of-bounds Write vulnerability could allow attackers to write data beyond allocated buffer boundaries leading to code execution or crashes.
An issue was discovered in ytnef before 1.9.1. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. This Out-of-bounds Read vulnerability could allow attackers to read data from memory outside the intended buffer boundaries.
An issue was discovered in ytnef before 1.9.1. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. This Out-of-bounds Read vulnerability could allow attackers to read data from memory outside the intended buffer boundaries.
An issue was discovered in ytnef before 1.9.1. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. This Integer Overflow vulnerability could allow attackers to cause unexpected behavior through arithmetic overflow.
An issue was discovered in ytnef before 1.9.1. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. This Integer Overflow vulnerability could allow attackers to cause unexpected behavior through arithmetic overflow.
An issue was discovered in ytnef before 1.9.1. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. This Out-of-bounds Read vulnerability could allow attackers to read data from memory outside the intended buffer boundaries.
An issue was discovered in ytnef before 1.9.1. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. This Buffer Overflow vulnerability could allow attackers to corrupt memory to execute arbitrary code or crash the application.
Buffer overflow in the built-in web server in DiskSavvy Enterprise 9.4.18 allows remote attackers to execute arbitrary code via a long URI in a GET request. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and EPSS exploitation probability 69.4%.
It was discovered that the zebra daemon in Quagga before 1.0.20161017 suffered from a stack-based buffer overflow when processing IPv6 Neighbor Discovery messages. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
The CClient::ProcessServerPacket method in engine/client/client.cpp in Teeworlds before 0.6.4 allows remote servers to write to arbitrary physical memory locations and possibly execute arbitrary code. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This Buffer Overflow vulnerability could allow attackers to corrupt memory to execute arbitrary code or crash the application.
Integer overflow in the mem_check_range function in drivers/infiniband/sw/rxe/rxe_mr.c in the Linux kernel before 4.9.10 allows local users to cause a denial of service (memory corruption), obtain. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity.
An exploitable out-of-bounds write vulnerability exists in the batch transaction field parsing functionality of Aerospike Database Server 3.10.0.3. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
GOM Player 2.3.10.5266 allows remote attackers to cause a denial of service (memory corruption) or possibly have unspecified other impact via a crafted fpx file. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. Public exploit code available and EPSS exploitation probability 44.8%.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. Public exploit code available and no vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated low severity (CVSS 3.7), this vulnerability is remotely exploitable, no authentication required. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 7.1), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 7.1), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in certain Apple products. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. No vendor patch available.