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 (36537)
Microsoft USBHUB 3.0 Device Driver Remote Code Execution Vulnerability. Rated medium severity (CVSS 6.8), 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.
Windows Media Remote Code Execution Vulnerability. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity.
Espeak-ng 1.52-dev was discovered to contain a Buffer Overflow via the function ReadClause at readclause.c. Rated medium severity (CVSS 5.3), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Espeak-ng 1.52-dev was discovered to contain a Stack Buffer Overflow via the function RemoveEnding at dictionary.c. Rated medium severity (CVSS 5.3), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Espeak-ng 1.52-dev was discovered to contain a Stack Buffer Underflow via the function CountVowelPosition at synthdata.c. Rated medium severity (CVSS 5.3), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Espeak-ng 1.52-dev was discovered to contain a buffer-overflow via the function SetUpPhonemeTable at synthdata.c. Rated medium severity (CVSS 5.3), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability has been identified in Opcenter Execution Foundation (All versions < V2407), Opcenter Quality (All versions < V2312), SIMATIC PCS neo (All versions < V4.1), SINEC NMS (All versions <. Rated high severity (CVSS 7.5), 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.
A vulnerability has been identified in Opcenter Execution Foundation (All versions < V2407), Opcenter Quality (All versions < V2312), SIMATIC PCS neo (All versions < V4.1), SINEC NMS (All versions <. Rated high severity (CVSS 7.5), 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.
Multiple memory corruption issues were addressed with improved input validation. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Multiple memory corruption issues were addressed with improved input validation. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Multiple memory corruption issues were addressed with improved input validation. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Multiple memory corruption issues were addressed with improved input validation. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Multiple memory corruption issues were addressed with improved input validation. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Multiple memory corruption issues were addressed with improved input validation. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Multiple memory corruption issues were addressed with improved input validation. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Multiple memory corruption issues were addressed with improved input validation. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Multiple memory corruption issues were addressed with improved input validation. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Multiple memory corruption issues were addressed with improved input validation. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Multiple memory corruption issues were addressed with improved input validation. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Multiple memory corruption issues were addressed with improved input validation. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Multiple memory corruption issues were addressed with improved input validation. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
An out-of-bounds read was addressed with improved bounds checking. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
The issue was addressed with improved memory handling. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
OpenEXR-viewer is a viewer for OpenEXR files with detailed metadata probing. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
TOTOLink A7000R V9.1.0u.6115_B20201022has a stack overflow vulnerability via setIpPortFilterRules. 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.
TOTOLink A7000R V9.1.0u.6115_B20201022 has a stack overflow vulnerability via setOpModeCfg. 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.
decToString in decNumber/decNumber.c in jq 88f01a7 has a one-byte out-of-bounds write via the " []-1.2e-1111111111" input. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
Heap Buffer Overflow vulnerability in GPAC version 2.3-DEV-rev617-g671976fcc-master, allows attackers to execute arbitrary code and cause a denial of service (DoS) via str2ulong class in. 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.
IBM Informix Dynamic Server 12.10 and 14.10 cdr is vulnerable to a heap buffer overflow, caused by improper bounds checking which could allow a local user to cause a segmentation fault. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. No vendor patch available.
IBM Informix Dynamic Server 12.10 and 14.10 archecker is vulnerable to a heap buffer overflow, caused by improper bounds checking which could allow a local user to cause a segmentation fault. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. No vendor patch available.
IBM Informix Dynamic Server 12.10 and 14.10 onsmsync is vulnerable to a heap buffer overflow, caused by improper bounds checking which could allow an attacker to execute arbitrary code. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
An out-of-bounds read vulnerability was found in smb2_dump_detail in fs/smb/client/smb2ops.c in the Linux Kernel. Rated high severity (CVSS 7.1), this vulnerability is low attack complexity. Public exploit code available and no vendor patch available.
An out-of-bounds read vulnerability was found in smbCalcSize in fs/smb/client/netmisc.c in the Linux Kernel. Rated high severity (CVSS 7.1), this vulnerability is low attack complexity. Public exploit code available and no vendor patch available.
In dhcp4_SetPDNAddress of dhcp4_Main.c, 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.
In Init of protocolnetadapter.cpp, there is a possible out of bounds read due to a missing bounds check. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. No vendor patch available.
In gpu_pixel_handle_buffer_liveness_update_ioctl of private/google-modules/gpu/mali_kbase/platform/pixel/pixel_gpu_slc.c, there is a possible out of bounds write due to improper input validation. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
In Init of protocolembmsadapter.cpp, there is a possible out of bounds read due to a missing bounds check. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. No vendor patch available.
In Init of protocolnetadapter.cpp, there is a possible out of bounds read due to a missing bounds check. Rated medium severity (CVSS 4.9), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
In SignalStrengthAdapter::FillGsmSignalStrength() of protocolmiscadapter.cpp, there is a possible out of bounds read due to a missing bounds check. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. No vendor patch available.
In cd_ParseMsg of cd_codec.c, there is a possible out of bounds read due to a missing bounds check. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In gpu_pixel_handle_buffer_liveness_update_ioctl of private/google-modules/gpu/mali_kbase/mali_kbase_core_linux.c, there is a possible out of bounds write due to an integer overflow. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
In ProtocolNetSimFileInfoAdapter() of protocolnetadapter.cpp, there is a possible out of bounds read due to a missing bounds check. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. No vendor patch available.
In ProtocolMiscCarrierConfigSimInfoIndAdapter of protocolmiscadapter.cpp, there is a possible out of bounds read due to a missing bounds check. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In sms_DecodeCodedTpMsg of sms_PduCodec.c, there is a possible out of bounds read due to a heap buffer overflow. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In GetSizeOfEenlRecords of protocoladapter.cpp, there is a possible out of bounds read due to an incorrect bounds check. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. No vendor patch available.
In ProtocolMiscATCommandAdapter::Init() of protocolmiscadapter.cpp, there is a possible out of bounds read due to a missing bounds check. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. No vendor patch available.
In ProtocolNetAcBarringInfo::ProtocolNetAcBarringInfo() of protocolnetadapter.cpp, there is a possible out of bounds read due to a missing bounds check. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In Init of protocolcalladapter.cpp, there is a possible out of bounds read due to a missing bounds check. Rated medium severity (CVSS 4.9), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
A buffer copy without checking size of input vulnerability has been reported to affect several QNAP operating system versions. Rated high severity (CVSS 7.2), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
A buffer copy without checking size of input vulnerability has been reported to affect several QNAP operating system versions. Rated high severity (CVSS 7.2), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
In Netgear Orbi RBR750 firmware before V7.2.6.21, there is a stack-based buffer overflow in /usr/sbin/httpd. 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.
Libde265 v1.0.14 was discovered to contain a global buffer overflow vulnerability in the read_coding_unit function at slice.cc. 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.
Libde265 v1.0.14 was discovered to contain a heap-buffer-overflow vulnerability in the derive_combined_bipredictive_merging_candidates function at motion.cc. 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.
Libde265 v1.0.14 was discovered to contain a heap-buffer-overflow vulnerability in the derive_spatial_luma_vector_prediction function at motion.cc. 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.
Tenda W30E V16.01.0.12(4843) contains a stack overflow vulnerability via the function formDeleteMeshNode. 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 AX3 V16.03.12.11 was discovered to contain a stack overflow via the function set_device_name. 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 W30E V16.01.0.12(4843) was discovered to contain a stack overflow via the function UploadCfg. 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 W30E V16.01.0.12(4843) was discovered to contain a stack overflow via the function formAdvancedSetListSet. 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 W30E V16.01.0.12(4843) was discovered to contain a stack overflow via the function formRebootMeshNode. 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 W30E V16.01.0.12(4843) was discovered to contain a stack overflow via the function formUpgradeMeshOnline. 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 W30E V16.01.0.12(4843) was discovered to contain a stack overflow via the function formResetMeshNode. 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 W30E V16.01.0.12(4843) was discovered to contain a command injection vulnerability via the function setUmountUSBPartition. 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 W30E V16.01.0.12(4843) was discovered to contain a stack overflow via the function via the function set_wan_status. 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 W30E V16.01.0.12(4843) was discovered to contain a command injection vulnerability via the function setFixTools. 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 W30E V16.01.0.12(4843) was discovered to contain a stack overflow via the function localMsg. 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 AX9 V22.03.01.46 has been found to contain a stack overflow vulnerability in the 'list' parameter at /goform/SetNetControlList. 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 AX9 V22.03.01.46 has been found to contain a stack overflow vulnerability in the 'list' parameter at /goform/SetVirtualServerCfg. 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 AX9 V22.03.01.46 has been found to contain a stack overflow vulnerability in the 'deviceList' parameter at /goform/setMacFilterCfg. 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 AX9 V22.03.01.46 has been found to contain a stack overflow vulnerability in the 'list' parameter at /goform/SetStaticRouteCfg. 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 AX12 V22.03.01.46 was discovered to contain a stack overflow via the list parameter at /goform/SetStaticRouteCfg. 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 AX12 V22.03.01.46 was discovered to contain a stack overflow via the deviceList parameter at /goform/setMacFilterCfg . 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 AX12 V22.03.01.46 was discovered to contain a stack overflow via the list parameter at /goform/SetVirtualServerCfg. 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.
strongSwan before 5.9.12 has a buffer overflow and possible unauthenticated remote code execution via a DH public value that exceeds the internal buffer in charon-tkm's DH proxy. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Improper input validation vulnerability in Samsung Open Source Escargot allows stack overflow and segmentation fault.0.0 through 4.0.0. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
An integer underflow vulnerability exists in the NTRIP Stream Parsing functionality of GPSd 3.25.1~dev. 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.
Improper size check vulnerability in softsimd prior to SMR Dec-2023 Release 1 allows stack-based buffer overflow. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
Out-of-bound write vulnerability in libsavsvc prior to SMR Dec-2023 Release 1 allows local attackers to execute arbitrary code. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
Integer overflow vulnerability in landmarkCopyImageToNative of libFacePreProcessingjni.camera.samsung.so prior to SMR Dec-2023 Release 1 allows attacker to trigger heap overflow. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
Integer overflow vulnerability in detectionFindFaceSupportMultiInstance of libFacePreProcessingjni.camera.samsung.so prior to SMR Dec-2023 Release 1 allows attacker to trigger heap overflow. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
Heap out-of-bounds write vulnerability in bootloader prior to SMR Dec-2023 Release 1 allows a physical attacker to execute arbitrary code. Rated medium severity (CVSS 6.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Heap out-of-bounds write vulnerability in dec_mono_audb of libsavsac.so prior to SMR Dec-2023 Release 1 allows an attacker to execute arbitrary code. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
Out of bounds write vulnerability in HDCP in HAL prior to SMR Dec-2023 Release 1 allows attacker to perform code execution. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
Out-of-bound write vulnerability in libIfaaCa prior to SMR Dec-2023 Release 1 allows local system attackers to execute arbitrary code. Rated medium severity (CVSS 6.7), this vulnerability is low attack complexity. No vendor patch available.
Memory corruption in Graphics Linux while assigning shared virtual memory region during IOCTL call. 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.
Memory corruption while submitting a large list of sync points in an AUX command to the IOCTL_KGSL_GPU_AUX_COMMAND. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity.
Transient DOS while parsing WPA IES, when it is passed with length more than expected size. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Transient DOS in WLAN Firmware while processing a FTMR frame. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Memory corruption while processing pin reply in Bluetooth, when pin code received from APP layer is greater than expected size. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. This Buffer Copy without Size Check vulnerability could allow attackers to overflow a buffer to corrupt adjacent memory.
Memory corruption when processing cmd parameters while parsing vdev. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
Memory corruption in Core while processing RX intent request. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. This Buffer Copy without Size Check vulnerability could allow attackers to overflow a buffer to corrupt adjacent memory.