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 (36625)
In apusys, there is a possible out of bounds write due to a missing bounds check. Rated medium severity (CVSS 6.7), this vulnerability is low attack complexity. No vendor patch available.
In apusys, there is a possible out of bounds write due to a missing bounds check. Rated medium severity (CVSS 6.7), this vulnerability is low attack complexity. No vendor patch available.
In BT firmware, there is a possible out of bounds write due to a missing bounds check. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A segmentation fault (SEGV) flaw was found in the Fribidi package and affects the fribidi_remove_bidi_marks() function of the lib/fribidi.c file. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available.
A heap-based buffer overflow flaw was found in the Fribidi package and affects the fribidi_cap_rtl_to_unicode() function of the fribidi-char-sets-cap-rtl.c file. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available.
A stack-based buffer overflow flaw was found in the Fribidi package. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
TOTOLINK A3002R TOTOLINK-A3002R-He-V1.1.1-B20200824.0128 is vulnerable Buffer Overflow via the hostname parameter in binary /bin/boa. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
TOTOLINK A3002R TOTOLINK-A3002R-He-V1.1.1-B20200824.0128 is vulnerable to Buffer Overflow via /bin/boa. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In TOTOLINK A860R V4.1.2cu.5182_B20201027, the parameters in infostat.cgi are not filtered, causing a buffer overflow vulnerability. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In TOTOLINK A860R V4.1.2cu.5182_B20201027, the main function in downloadfile.cgi has a buffer overflow vulnerability. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
TOTOLINK A860R V4.1.2cu.5182_B20201027 is vulnerable to Buffer Overflow via Cstecgi.cgi. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In Tenda G3 US_G3V3.0br_V15.11.0.6(7663)_EN_TDE, the getsinglepppuser function has a buffer overflow caused by sscanf. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This Buffer Copy without Size Check vulnerability could allow attackers to overflow a buffer to corrupt adjacent memory.
Using snakeYAML to parse untrusted YAML files may be vulnerable to Denial of Service attacks (DOS). Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Using snakeYAML to parse untrusted YAML files may be vulnerable to Denial of Service attacks (DOS). Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Using snakeYAML to parse untrusted YAML files may be vulnerable to Denial of Service attacks (DOS). Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Using snakeYAML to parse untrusted YAML files may be vulnerable to Denial of Service attacks (DOS). Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
123elf Lotus 1-2-3 before 1.0.0rc3 for Linux, and Lotus 1-2-3 R3 for UNIX and other platforms through 9.8.2, allow attackers to execute arbitrary code via a crafted worksheet. 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 the Linux kernel before 5.19. Rated medium severity (CVSS 6.1), 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 PSPP 1.6.2. 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 PSPP 1.6.2. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
PKUVCL davs2 v1.6.205 was discovered to contain a global buffer overflow via the function parse_sequence_header() at source/common/header.cc:269. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Memory corruption in multimedia due to buffer overflow while processing count variable from client in Snapdragon Auto. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
Memory corruption in video driver due to double free while parsing ASF clip in Snapdragon Auto, Snapdragon Compute, Snapdragon Connectivity, Snapdragon Consumer IOT, Snapdragon Industrial IOT,. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Memory corruption due to buffer overflow while parsing MKV clips with invalid bitmap size in Snapdragon Auto, Snapdragon Compute, Snapdragon Connectivity, Snapdragon Consumer IOT, Snapdragon. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Memory corruption due to incorrect pointer arithmetic when attempting to change the endianness in video parser function in Snapdragon Auto, Snapdragon Compute, Snapdragon Connectivity, Snapdragon. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Memory corruption due to buffer overflow occurs while processing invalid MKV clip which has invalid seek header in Snapdragon Auto, Snapdragon Compute, Snapdragon Connectivity, Snapdragon Industrial. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Memory corruption in multimedia due to improper length check while copying the data in Snapdragon Auto. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
Memory corruption in multimedia due to improper check on the messages received. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
Memory corruption in multimedia due to incorrect type conversion while adding data in Snapdragon Auto. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
Memory corruption in multimedia due to improper check on received export descriptors in Snapdragon Auto. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
Memory corruption in multimedia due to improper validation of array index in Snapdragon Auto. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
Memory corruption in multimedia driver due to untrusted pointer dereference while reading data from socket in Snapdragon Auto. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
Memory corruption in graphic driver due to use after free while calling multiple threads application to driver. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity.
Memory corruption in Bluetooth HOST due to stack-based buffer overflow when when extracting data using command length parameter in Snapdragon Connectivity, Snapdragon Mobile. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, 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.
Improper validation of backend id in PCM routing process can lead to memory corruption in Snapdragon Auto, Snapdragon Compute, Snapdragon Connectivity, Snapdragon Consumer IOT, Snapdragon Industrial. Rated high severity (CVSS 7.8), this vulnerability is 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.
Memory corruption in audio due to lack of check of invalid routing address into APR Routing table in Snapdragon Auto, Snapdragon Compute, Snapdragon Connectivity, Snapdragon Consumer IOT, Snapdragon. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
An out-of-bounds read can occur while parsing a server certificate due to improper length check in Snapdragon Auto, Snapdragon Compute, Snapdragon Connectivity, Snapdragon Consumer Electronics. Rated critical severity (CVSS 9.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Memory corruption due to out of bound read while parsing a video file in Snapdragon Auto, Snapdragon Compute, Snapdragon Connectivity, Snapdragon Industrial IOT, Snapdragon Mobile. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
An integer coercion error was found in the openvswitch kernel module. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. Public exploit code available.
A flaw was found in the Xorg-x11-server. Rated high severity (CVSS 7.8), this vulnerability is 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.
A flaw was found in the Xorg-x11-server. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity.
Contiki-NG is an open-source, cross-platform operating system for Next-Generation IoT devices. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, 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.
Contiki-NG is an open-source, cross-platform operating system for Next-Generation IoT devices. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Contiki-NG is an open-source, cross-platform operating system for Next-Generation IoT devices. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. This Out-of-bounds Read vulnerability could allow attackers to read data from memory outside the intended buffer boundaries.
D-link DIR-816 A2_v1.10CNB04, DIR-878 DIR_878_FW1.30B08.img is vulnerable to Buffer Overflow via /goform/addRouting. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Measuresoft ScadaPro Server (All Versions) allows use after free while processing a specific project file. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Measuresoft ScadaPro Server (All Versions) uses unmaintained ActiveX controls. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Measuresoft ScadaPro Server (Versions prior to 6.8.0.1) uses an unmaintained ActiveX control, which may allow an out-of-bounds write condition while processing a specific project file. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity.
Tenda AC9 V15.03.05.19 was discovered to contain a stack overflow via the mask parameter at /goform/WanParameterSetting. Rated high severity (CVSS 7.2), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Tenda AC9 V15.03.05.19 was discovered to contain a stack overflow via the time parameter at /goform/SetLEDCfg. Rated high severity (CVSS 7.2), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Tenda AC9 V15.03.05.19 was discovered to contain a stack overflow via the deviceList parameter at /goform/setMacFilterCfg. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Tenda AC9 V15.03.05.19 was discovered to contain a stack overflow via the list parameter at /goform/setPptpUserList. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
In subsys/net/ip/tcp.c , function tcp_flags , when the incoming parameter flags is ECN or CWR , the buf will out-of-bounds write a byte zero. Rated medium severity (CVSS 5.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
A race condition was found in the Linux kernel's IP framework for transforming packets (XFRM subsystem) when multiple calls to xfrm_probe_algs occurred simultaneously. Rated high severity (CVSS 7.0).
FATEK FvDesigner version 1.5.103 and prior is vulnerable to an out-of-bounds write while processing project files. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
MOXA NPort 5110: Firmware Versions 2.10 is vulnerable to an out-of-bounds write that may allow an attacker to overwrite values in memory, causing a denial-of-service condition or potentially bricking. Rated high severity (CVSS 8.2), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
MOXA NPort 5110: Firmware Versions 2.10 is vulnerable to an out-of-bounds write that can cause the device to become unresponsive. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A flaw was found in the Linux kernel’s implementation of IO-URING. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. This Use After Free vulnerability could allow attackers to access freed memory to execute arbitrary code or crash the application.
Alpha7 PC Loader (All versions) is vulnerable to a stack-based buffer overflow while processing a specifically crafted project file, which may allow an attacker to execute arbitrary code. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
An out-of-bounds read flaw was found in the Linux kernel’s io_uring module in the way a user triggers the io_read() function with some special parameters. Rated medium severity (CVSS 6.1), this vulnerability is low attack complexity.
CNCSoft: All versions prior to 1.01.32 does not properly sanitize input while processing a specific project file, allowing a possible stack-based buffer overflow condition. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity.
Delta Electronics CNCSoft (All versions prior to 1.01.32) does not properly sanitize input while processing a specific project file, allowing a possible out-of-bounds read condition. Rated high severity (CVSS 7.1), this vulnerability is no authentication required, low attack complexity.
A stack buffer overflow flaw was found in Libtiffs' tiffcp.c in main() function. Rated medium severity (CVSS 6.1), this vulnerability is no authentication required, low attack complexity. Public exploit code available.
A heap buffer overflow flaw was found in Libtiffs' tiffinfo.c in TIFFReadRawDataStriped() function. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available.
Freeciv before 2.6.7 and before 3.0.3 is prone to a buffer overflow vulnerability in the Modpack Installer utility's handling of the modpack URL. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. This Buffer Copy without Size Check vulnerability could allow attackers to overflow a buffer to corrupt adjacent memory.
Realtek Linux/Android Bluetooth Mesh SDK has a buffer overflow vulnerability due to insufficient validation for segmented packets’ link parameter. Rated medium severity (CVSS 6.5), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Realtek Linux/Android Bluetooth Mesh SDK has a buffer overflow vulnerability due to insufficient validation for the length of segmented packets’ shift parameter. Rated medium severity (CVSS 6.5), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Realtek Linux/Android Bluetooth Mesh SDK has a buffer overflow vulnerability due to insufficient validation for the size of segmented packets’ reference parameter. Rated medium severity (CVSS 6.5), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Realtek Linux/Android Bluetooth Mesh SDK has a buffer overflow vulnerability due to insufficient validation for broadcast network packet length. Rated medium severity (CVSS 6.5), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Xpdf prior to 4.04 lacked an integer overflow check in JPXStream.cc. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
LibTIFF 4.4.0 has an out-of-bounds read in extractImageSection in tools/tiffcrop.c:6905, allowing attackers to cause a denial-of-service via a crafted tiff file. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available.
A heap-buffer-overflow flaw was found in ImageMagick’s PushShortPixel() function of quantum-private.h file. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available.
A vulnerbiility was found in Openscad, where a .scad file with no trailing newline could cause an out-of-bounds read during parsing of annotations. Rated high severity (CVSS 7.1), this vulnerability is no authentication required, low attack complexity. Public exploit code available.
A vulnerbiility was found in Openscad, where a DXF-format drawing with particular (not necessarily malformed!) properties may cause an out-of-bounds memory access when imported using import(). Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available.
An out-of-bounds read vulnerability was discovered in linux kernel in the smc protocol stack, causing remote dos. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A heap-based buffer overflow flaw was found in libmodbus in function modbus_reply() in src/modbus.c. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. Public exploit code available.
A heap-based-buffer-over-read flaw was found in ImageMagick's GetPixelAlpha() function of 'pixel-accessor.h'. Rated high severity (CVSS 7.1), this vulnerability is no authentication required, low attack complexity. Public exploit code available.
Advancecomp v2.3 was discovered to contain a heap buffer overflow via the component __interceptor_memcpy at /sanitizer_common/sanitizer_common_interceptors.inc. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Advancecomp v2.3 was discovered to contain a heap buffer overflow. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Advancecomp v2.3 was discovered to contain a heap buffer overflow. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Advancecomp v2.3 was discovered to contain a heap buffer overflow via le_uint32_read at /lib/endianrw.h. Rated medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
An issue was discovered on certain DrayTek Vigor routers before July 2022 such as the Vigor3910 before 4.3.1.1. 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.
Tenda_TX9pro V22.03.02.10 was discovered to contain a buffer overflow via the component httpd/SetNetControlList. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. Public exploit code available and no vendor patch available.
Tenda M3 V1.0.0.12(4856) was discovered to contain a buffer overflow in the function formSetGuideListItem. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Tenda M3 V1.0.0.12(4856) was discovered to contain a stack overflow in the function formDelPushedAd. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Tenda M3 V1.0.0.12(4856) was discovered to contain a stack overflow in the function formDelAd. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Tenda M3 V1.0.0.12(4856) was discovered to contain a heap buffer overflow vulnerability in the function formSetFixTools. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Tenda M3 V1.0.0.12(4856) was discovered to contain a stack overflow vulnerability in the function formSetAdConfigInfo. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Tenda M3 V1.0.0.12(4856) was discovered to contain a heap buffer overflow vulnerability in the function formEmailTest. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Tenda M3 V1.0.0.12(4856) was discovered to contain a heap buffer overflow vulnerability in the function formEmailTest. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.