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 (5254)
A buffer overflow in the g_cfg.MaxUsers component of LightFTP v2.0 allows attackers to cause a Denial of Service (DoS) via a crafted input.
A buffer overflow vulnerability exists in the Modbus TCP functionality of Socomec DIRIS Digiware M-70 1.6.9. A specially crafted set of network packets can lead to denial of service. An attacker can send a sequence of unauthenticated packets to trigger this vulnerability.
Heap-based Buffer Overflow, Out-of-bounds Write vulnerability in Avast Antivirus on MacOS of a crafted Mach-O file may allow Local Execution of Code or Denial of Service of antivirus protection. This issue affects Antivirus: from 15.7 before 3.9.2025.
FeehiCMS version 2.1.1 fails to enforce server-side immutability for parameters that are presented to clients as "read-only." An authenticated attacker can intercept and modify the parameter in transit and the backend accepts the changes. This can lead to unintended username changes.
Insufficient argument validation in OpenVPN 2.7_alpha1 through 2.7_rc1 allows an attacker to trigger a heap buffer over-read when parsing IP addresses
An unauthenticated remote attacker, who beats a race condition, can exploit a flaw in the communication servers of the CODESYS Control runtime system on Linux and QNX to trigger an out-of-bounds read via crafted socket communication, potentially causing a denial of service.
AIS-catcher is a multi-platform AIS receiver. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
AIS-catcher is a multi-platform AIS receiver. Rated critical severity (CVSS 9.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
Out-of-bounds memory operations in org.lz4:lz4-java 1.8.0 and earlier allow remote attackers to cause denial of service and read adjacent memory via untrusted compressed input. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Stack-based Buffer Overflow vulnerability in ABB Terra AC wallbox.8.33. Rated medium severity (CVSS 6.9), this vulnerability is low attack complexity. No vendor patch available.
Vulnerability of accessing invalid memory in the component driver module. Rated medium severity (CVSS 6.6), this vulnerability is low attack complexity. No vendor patch available.
Versions of the package validator before 13.15.22 are vulnerable to Incomplete Filtering of One or More Instances of Special Elements in the isLength() function that does not take into account. Rated high severity (CVSS 7.7), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
Forge (also called `node-forge`) is a native implementation of Transport Layer Security in JavaScript. Rated medium severity (CVSS 6.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This Integer Overflow vulnerability could allow attackers to cause unexpected behavior through arithmetic overflow.
Suricata is a network IDS, IPS and NSM engine developed by the OISF (Open Information Security Foundation) and the Suricata community. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
Suricata is a network IDS, IPS and NSM engine developed by the OISF (Open Information Security Foundation) and the Suricata community. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Suricata is a network IDS, IPS and NSM engine developed by the OISF (Open Information Security Foundation) and the Suricata community. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
Suricata is a network IDS, IPS and NSM engine developed by the OISF (Open Information Security Foundation) and the Suricata community. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Suricata is a network IDS, IPS and NSM engine developed by the OISF (Open Information Security Foundation) and the Suricata community. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
Zenitel TCIV-3+ is vulnerable to an out-of-bounds write vulnerability, which could allow a remote attacker to crash the device. Rated high severity (CVSS 7.0), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Tinyproxy through 1.11.2 contains an integer overflow vulnerability in the strip_return_port() function within src/reqs.c. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
FAST FAC1200R F400_FAC1200R_Q is vulnerable to Buffer Overflow in the function sub_80435780 via the parameter string fac_password. 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.
FAST FAC1200R F400_FAC1200R_Q is vulnerable to Buffer Overflow in the function sub_80435780 via the parameter password. 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.
A heap-based buffer overflow vulnerability exists in the glib library's g_escape_uri_string() function due to an integer overflow in buffer size calculation when processing strings with a very large number of characters requiring URI escaping. This vulnerability affects multiple Red Hat Enterprise Linux 9.0 and 10.0 distributions across various architectures (x86_64, ARM64, IBM Z, Power). A proof-of-concept exploit is publicly available, though EPSS scoring indicates only 0.01% exploitation probability (1st percentile), suggesting limited active exploitation in the wild despite the availability of exploit code.
Out-of-bounds Read vulnerability in ASR1903、ASR3901 in ASR Lapwing_Linux on Linux (nr_fw modules). Rated high severity (CVSS 7.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
There is a potential OOB Write vulnerability in the gen_prov_start function in pb_adv.c. Rated high severity (CVSS 7.6), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
An out-of-bound write can lead to an arbitrary code execution. Rated high severity (CVSS 7.6), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
In KDE Krita before 5.2.13, loading a manipulated TGA file could result in a heap-based buffer overflow in plugins/impex/tga/kis_tga_import.cpp (aka KisTgaImport). Rated medium severity (CVSS 6.7), this vulnerability is no authentication required. No vendor patch available.
Stack-based buffer overflow in Azure Application Gateway allows an unauthorized attacker to elevate privileges over a network. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Out-of-bounds read in Application Gateway allows an unauthorized attacker to elevate privileges over a network. Rated critical severity (CVSS 9.4), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
WebAssembly Micro Runtime (WAMR) is a lightweight standalone WebAssembly (Wasm) runtime. Rated medium severity (CVSS 5.1), this vulnerability is no authentication required. Public exploit code available and no vendor patch available.
A Heap-based Buffer Overflow vulnerability is present in Ashlar-Vellum Cobalt, Xenon, Argon, Lithium, and Cobalt Share versions 12.6.1204.207 and prior that could allow an attacker to disclose. Rated high severity (CVSS 8.4), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
An Out-of-Bounds Write vulnerability is present in Ashlar-Vellum Cobalt, Xenon, Argon, Lithium, and Cobalt Share versions 12.6.1204.207 and prior that could allow an attacker to disclose information. Rated high severity (CVSS 8.4), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
NVIDIA DGX Spark GB10 contains a vulnerability in SROOT firmware, where an attacker could cause unexpected memory buffer operations. Rated medium severity (CVSS 4.4), this vulnerability is low attack complexity. No vendor patch available.
NVIDIA DGX Spark GB10 contains a vulnerability in SROOT firmware where an attacker could cause an out-of-bound write. Rated medium severity (CVSS 6.7), this vulnerability is low attack complexity. No vendor patch available.
NVIDIA DGX Spark GB10 contains a vulnerability in SROOT firmware, where an attacker could cause an out-of-bound write. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
Security Point (Windows) of MaLion and MaLionCloud contains a heap-based buffer overflow vulnerability in processing Content-Length. Rated critical severity (CVSS 9.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Security Point (Windows) of MaLion and MaLionCloud contains a stack-based buffer overflow vulnerability in processing HTTP headers. Rated critical severity (CVSS 9.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A stack buffer overflow vulnerability has been identified in certain router models. Rated medium severity (CVSS 6.9), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
A flaw was found in WebKitGTK and WPE WebKit. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. Rated high severity (CVSS 7.1), this vulnerability is no authentication required, low attack complexity. Public exploit code available.
LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. Rated high severity (CVSS 7.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. Rated medium severity (CVSS 6.1), 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.
LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. Rated medium severity (CVSS 6.1), 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.
Improper input validation within the XOCL driver may allow a local attacker to generate an integer overflow condition, potentially resulting in loss of confidentiality or availability. Rated high severity (CVSS 8.0), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Improper input validation within AMD uProf can allow a local attacker to write out of bounds, potentially resulting in a crash or denial of service. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. No vendor patch available.
A buffer overflow with Xilinx Run Time Environment may allow a local attacker to read or corrupt data from the advanced extensible interface (AXI), potentially resulting in loss of confidentiality,. Rated high severity (CVSS 7.3), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
The extract_name function in Fluent Bit in_docker input plugin copies container names into a fixed size stack buffer without validating length. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
A security vulnerability has been detected in jarun nnn up to 5.1. Rated medium severity (CVSS 4.8), this vulnerability is low attack complexity. No vendor patch available.
A weakness has been identified in D-Link DWR-M920 1.1.50. Rated high severity (CVSS 7.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A security flaw has been discovered in D-Link DIR-822K and DWR-M920 1.00_20250513164613/1.1.50. Rated high severity (CVSS 7.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability was identified in D-Link DIR-822K and DWR-M920 1.00_20250513164613/1.1.50. Rated high severity (CVSS 7.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability was determined in D-Link DIR-822K and DWR-M920 1.00_20250513164613/1.1.50. Rated high severity (CVSS 7.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability was found in D-Link DIR-822K 1.00. Rated high severity (CVSS 7.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability has been found in D-Link DIR-822K and DWR-M920 1.00_20250513164613/1.1.50. Rated high severity (CVSS 7.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A flaw has been found in D-Link DIR-822K and DWR-M920 1.00_20250513164613/1.1.50. Rated high severity (CVSS 7.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Integer Underflow Leads to Out-of-Bounds Access in XChaCha20-Poly1305 Decrypt. Rated low severity (CVSS 2.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
PJSIP is a free and open source multimedia communication library. Rated high severity (CVSS 8.7), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
ESF-IDF is the Espressif Internet of Things (IOT) Development Framework. Rated medium severity (CVSS 6.9), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An out-of-bounds read was addressed with improved bounds checking. Rated medium severity (CVSS 4.3), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
MLX is an array framework for machine learning on Apple silicon. Rated medium severity (CVSS 5.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
vLLM is an inference and serving engine for large language models (LLMs). Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity.
cups-filters contains backends, filters, and other software required to get the cups printing service working on operating systems other than macos. Rated low severity (CVSS 3.3), this vulnerability is low attack complexity. Public exploit code available.
The fetch function in file thinkphp\library\think\Template.php in ThinkPHP 5.0.24 allows attackers to read arbitrary files via crafted file path in a template value. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Tenda AC21 V16.03.08.16 is vulnerable to Buffer Overflow via the deviceId parameter in /goform/saveParentControlInfo. Rated medium severity (CVSS 4.3), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Tenda AC21 V16.03.08.16 is vulnerable to Buffer Overflow via the urls parameter of /goform/saveParentControlInfo. Rated medium severity (CVSS 4.3), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Tenda AC21 V16.03.08.16 is vulnerable to Buffer Overflow via the rebootTime parameter of /goform/SetSysAutoRebbotCfg. Rated medium severity (CVSS 4.3), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Tenda AC21 V16.03.08.16 is vulnerable to Buffer Overflow via the list parameter of /goform/setPptpUserList. Rated medium severity (CVSS 4.3), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Tenda AC21 V16.03.08.16 is vulnerable to Buffer Overflow in: /goform/SetVirtualServerCfg via the list parameter. Rated medium severity (CVSS 4.3), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
A Stack-based buffer overflow vulnerability in the SonicOS SSLVPN service allows a remote unauthenticated attacker to cause Denial of Service (DoS), which could cause an impacted firewall to crash. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A vulnerability has been found in Tenda AC21 16.03.08.16. Rated high severity (CVSS 7.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A flaw has been found in Tenda AC21 16.03.08.16. Rated high severity (CVSS 7.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
SSH Agent servers do not validate the size of messages when processing new identity requests, which may cause the program to panic if the message is malformed due to an out of bounds read. Rated medium severity (CVSS 5.3), this vulnerability is remotely exploitable, 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.
A vulnerability was detected in Tenda CH22 1.0.0.1. Rated high severity (CVSS 7.4), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Out-of-bounds Read in Shelly Pro 3EM (before v1.4.4) allows Overread Buffers. Rated high severity (CVSS 8.3), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Multiple vulnerabilities exist in cbor2 through version 5.7.0 in the decode_definite_long_string() function of the C extension decoder (source/decoder.c): (1) Integer Underflow Leading to. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
A stack-based buffer overflow vulnerability in Fortinet FortiOS 7.6.0 through 7.6.3, FortiOS 7.4.0 through 7.4.8, FortiOS 7.2 all versions, FortiOS 7.0 all versions, FortiOS 6.4 all versions, FortiOS. Rated high severity (CVSS 7.5), this vulnerability is no authentication required. No vendor patch available.
A stack-based buffer overflow vulnerability in Fortinet FortiOS 7.6.0 through 7.6.3, FortiOS 7.4.0 through 7.4.8, FortiOS 7.2 all versions, FortiOS 7.0 all versions, FortiOS 6.4 all versions allows. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable. No vendor patch available.
An Out-of-bounds Write vulnerability [CWE-787] in FortiADC 8.0.0, 7.6.0 through 7.6.2, 7.4.0 through 7.4.7, 7.2 all versions, 7.1 all versions, 7.0 all versions, 6.2 all versions may allow an. Rated medium severity (CVSS 6.6), this vulnerability is remotely exploitable. No vendor patch available.
A buffer copy without checking size of input ('classic buffer overflow') vulnerability in Fortinet FortiExtender 7.6.0 through 7.6.1, FortiExtender 7.4.0 through 7.4.6, FortiExtender 7.2 all. Rated medium severity (CVSS 6.4). No vendor patch available.
A Heap-based Buffer Overflow vulnerability [CWE-122] vulnerability in Fortinet FortiClientWindows 7.4.0 through 7.4.3, FortiClientWindows 7.2.0 through 7.2.8 may allow an authenticated local IPSec. Rated high severity (CVSS 7.8). No vendor patch available.
A vulnerability was discovered in Awesome Miner thru 11.2.4 that allows arbitrary read and write to kernel memory and MSRs (such as LSTAR) as an unprivileged user. Rated high severity (CVSS 7.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
A malicious client acting as the receiver of an rsync file transfer can trigger an out of bounds read of a heap based buffer, via a negative array index. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
There is a vulnerability in the Supermicro BMC web function at Supermicro MBD-X13SEDW-F. Rated high severity (CVSS 7.2), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Stack buffer overflow vulnerability exists in the Supermicro BMC Shared library. Rated medium severity (CVSS 5.5), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
There is a vulnerability in the Supermicro BMC web function at Supermicro MBD-X13SEDW-F. Rated high severity (CVSS 7.2), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Stack-based buffer overflow in the SMASH-CLP shell. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
A buffer overflow vulnerability exists in the CvManager functionality of Dell ControlVault3 prior to 5.15.14.19 and Dell ControlVault3 Plus prior to 6.2.36.47. Rated high severity (CVSS 8.8), this vulnerability is low attack complexity. No vendor patch available.
Multiple out-of-bounds read and write vulnerabilities exist in the ControlVault WBDI Driver Broadcom Storage Adapter functionality of Dell ControlVault3 prior to 5.15.14.19 and Dell ControlVault3. Rated high severity (CVSS 7.3), this vulnerability is low attack complexity. No vendor patch available.
Multiple out-of-bounds read and write vulnerabilities exist in the ControlVault WBDI Driver Broadcom Storage Adapter functionality of Dell ControlVault3 prior to 5.15.14.19 and Dell ControlVault3. Rated high severity (CVSS 7.3), this vulnerability is low attack complexity. No vendor patch available.
Multiple out-of-bounds read and write vulnerabilities exist in the ControlVault WBDI Driver Broadcom Storage Adapter functionality of Dell ControlVault3 prior to 5.15.14.19 and Dell ControlVault3. Rated high severity (CVSS 7.3), this vulnerability is low attack complexity. No vendor patch available.