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 (36525)
Memory corruption in Kernel while handling GPU operations. 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.
Memory corruption while allocating memory for graphics. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
Memory corruption when there is failed unmap operation in GPU. 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.
Memory corruption while processing Codec2 during v13k decoder pitch synthesis. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
In imgsys, there is a possible information disclosure due to a missing bounds check. Rated medium severity (CVSS 6.3). No vendor patch available.
In gnss, there is a possible escalation of privilege due to a missing bounds check. Rated medium severity (CVSS 6.6), this vulnerability is remotely exploitable. No vendor patch available.
In flashc, there is a possible out of bounds write due to an uncaught exception. Rated high severity (CVSS 8.4), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
In battery, there is a possible out of bounds read due to an integer overflow. Rated medium severity (CVSS 5.4), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
In audio, there is a possible out of bounds read due to an incorrect calculation of buffer size. Rated low severity (CVSS 2.3), this vulnerability is low attack complexity. No vendor patch available.
In da, there is a possible out of bounds write due to a missing bounds check. Rated medium severity (CVSS 6.6), this vulnerability is remotely exploitable. No vendor patch available.
In da, there is a possible out of bounds write due to a missing bounds check. Rated medium severity (CVSS 6.6), this vulnerability is remotely exploitable. No vendor patch available.
In da, there is a possible out of bounds write due to a missing bounds check. Rated medium severity (CVSS 6.6), this vulnerability is remotely exploitable. No vendor patch available.
In da, there is a possible out of bounds read due to a missing bounds check. Rated medium severity (CVSS 4.4), this vulnerability is remotely exploitable. No vendor patch available.
In wlan firmware, there is a possible out of bounds write due to improper input validation. Rated high severity (CVSS 8.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
In modem protocol, there is a possible out of bounds write due to a missing bounds check. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Dlink Dir-3040us A1 1.20b03a hotfix is vulnerable to Buffer Overflow. Rated high severity (CVSS 7.3), this vulnerability is low attack complexity. No vendor patch available.
Tenda F1202 v1.2.0.20(408) has a stack overflow vulnerability in the page parameter of fromAddressNat function. Rated medium severity (CVSS 6.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Tenda F1202 v1.2.0.20(408) has a stack overflow vulnerability via the entrys parameter in the fromAddressNat function. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Tenda F1202 v1.2.0.20(408) has a stack overflow vulnerability via the PPPOEPassword parameter in the formQuickIndex function. Rated medium severity (CVSS 6.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Tenda F1202 v1.2.0.20(408) has a stack overflow vulnerability located in the funcpara1 parameter in the formSetCfm function. 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 F1202 v1.2.0.20(408) has a stack overflow vulnerability via the mitInterface parameter in the fromAddressNat function. Rated high severity (CVSS 8.0), this vulnerability is low attack complexity. Public exploit code available and no vendor patch available.
Tenda FH1205 v2.0.0.7(775) has a stack overflow vulnerability in the security parameter from the formWifiBasicSet function. Rated medium severity (CVSS 6.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Tenda FH1205 v2.0.0.7(775) has a stack overflow vulnerability in the security_5g parameter from formWifiBasicSet function. Rated medium severity (CVSS 6.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Tenda FH1205 v2.0.0.7(775) has a stack overflow vulnerability in the schedStartTime parameter from setSchedWifi function. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Tenda FH1205 v2.0.0.7(775) has a stack overflow vulnerability in the time parameter from saveParentControlInfo function. 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 FH1205 v2.0.0.7(775) has a stack overflow vulnerability in the list1 parameter from fromDhcpListClient function. Rated medium severity (CVSS 5.7), this vulnerability is low attack complexity. Public exploit code available and no vendor patch available.
Tenda FH1205 v2.0.0.7(775) has a stack overflow vulnerability in the page parameter from fromAddressNat function. 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 FH1205 v2.0.0.7(775) has a stack overflow vulnerability in the deviceId parameter from saveParentControlInfo function. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Tenda FH1205 v2.0.0.7(775) has a stack overflow vulnerability in the schedEndTime parameter from setSchedWifi function. Rated high severity (CVSS 8.0), this vulnerability is low attack complexity. Public exploit code available and no vendor patch available.
Tenda FH1205 v2.0.0.7(775) has a stack overflow vulnerability in the entrys parameter from fromAddressNat function. Rated high severity (CVSS 8.0), this vulnerability is low attack complexity. Public exploit code available and no vendor patch available.
Tenda FH1205 v2.0.0.7(775) has a stack overflow vulnerability in the urls parameter from saveParentControlInfo function. Rated high severity (CVSS 8.8), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Tenda FH1205 v2.0.0.7(775) has a stack overflow vulnerability in the page parameter from fromDhcpListClient function. Rated medium severity (CVSS 6.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Tenda FH1205 v2.0.0.7(775) has a stack overflow vulnerability in the mitInterface parameter from fromAddressNat function. 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 AC15 v15.03.05.18 has a stack overflow vulnerability in the time parameter from the setSmartPowerManagement function. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
An malicious BLE device can crash BLE victim device by sending malformed gatt packet. Rated medium severity (CVSS 6.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Tenda AC10U v15.03.06.48 has a stack overflow vulnerability in the deviceId, limitSpeed, limitSpeedUp parameter from formSetClientState function. Rated high severity (CVSS 8.1), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Tenda FH1203 v2.0.1.6 has a stack overflow vulnerability in the list1 parameter of the fromDhcpListClient function. 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 FH1203 v2.0.1.6 has a stack overflow vulnerability in the urls parameter of the saveParentControlInfo function. Rated medium severity (CVSS 6.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Tenda FH1203 v2.0.1.6 has a stack overflow vulnerability in the schedStartTime parameter of the setSchedWifi function. 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 FH1203 v2.0.1.6 has a stack overflow vulnerability in the time parameter of the saveParentControlInfo function. Rated high severity (CVSS 8.0), this vulnerability is low attack complexity. Public exploit code available and no vendor patch available.
Tenda FH1203 v2.0.1.6 has a stack overflow vulnerability in the schedEndTime parameter of the setSchedWifi function. Rated high severity (CVSS 8.0), this vulnerability is low attack complexity. Public exploit code available and no vendor patch available.
Tenda FH1203 v2.0.1.6 has a stack overflow vulnerability in the deviceMac parameter of the addWifiMacFilter function. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Tenda FH1203 v2.0.1.6 firmware has a stack overflow vulnerability in the security_5g parameter of the formWifiBasicSet function. Rated medium severity (CVSS 6.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Tenda FH1203 v2.0.1.6 firmware has a stack overflow vulnerability in the security parameter of the formWifiBasicSet function. Rated medium severity (CVSS 6.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Tenda FH1203 v2.0.1.6 has a stack overflow vulnerability in the deviceId parameter of the saveParentControlInfo function. Rated high severity (CVSS 8.0), this vulnerability is low attack complexity. Public exploit code available and no vendor patch available.
Tenda FH1203 v2.0.1.6 has a stack overflow vulnerability in the page parameter of the fromDhcpListClient function. Rated high severity (CVSS 8.0), this vulnerability is low attack complexity. Public exploit code available and no vendor patch available.
Tenda FH1202 v1.2.0.14(408) has a stack overflow vulnerability in the page parameter of the fromAddressNat function. Rated high severity (CVSS 8.0), this vulnerability is low attack complexity. Public exploit code available and no vendor patch available.
Tenda FH1202 v1.2.0.14(408) has a stack overflow vulnerability in the time parameter of the saveParentControlInfo function. Rated high severity (CVSS 8.8), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Tenda FH1202 v1.2.0.14(408) has a stack overflow vulnerability in the schedEndTime parameter of the setSchedWifi function. Rated medium severity (CVSS 6.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Tenda FH1202 v1.2.0.14(408) firmware has a stack overflow vulnerability in the entrys parameter of the fromAddressNat function. 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 FH1202 v1.2.0.14(408) has a stack overflow vulnerability in the schedStartTime parameter of the setSchedWifi function. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Tenda FH1202 v1.2.0.14(408) has a stack overflow vulnerability in the urls parameter of the saveParentControlInfo function. 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 FH1202 v1.2.0.14(408) has a stack overflow vulnerability in the security_5g parameter of the formWifiBasicSet function. Rated medium severity (CVSS 6.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Tenda FH1202 v1.2.0.14(408) has a stack overflow vulnerability in the deviceId parameter of the saveParentControlInfo function. Rated medium severity (CVSS 6.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Tenda FH1202 v1.2.0.14(408) has a stack overflow vulnerability in the security parameter of the formWifiBasicSet function. 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 FH1202 v1.2.0.14(408) has a stack overflow vulnerability in the mitInterface parameter of the fromAddressNat function. Rated high severity (CVSS 8.0), this vulnerability is low attack complexity. Public exploit code available and no vendor patch available.
Tenda FH1202 v1.2.0.14(408) has a stack overflow vulnerability in the deviceId parameter of the formSetDeviceName function. 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 FH1202 v1.2.0.14(408) has a stack overflow vulnerability in the deviceMac parameter of the addWifiMacFilter function. Rated medium severity (CVSS 6.5), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
Tenda FH1202 v1.2.0.14(408) has a stack overflow vulnerability located in the deviceName parameter of the formSetDeviceName function. 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 FH1202 v1.2.0.14(408) has a stack overflow vulnerability in the deviceId parameter of the addWifiMacFilter function. 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 vulnerability was found in appneta tcpreplay up to 4.4.4. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. Public exploit code available and no vendor patch available.
Stack-based Buffer Overflow vulnerability in NEC Corporation Aterm WG1800HP4, WG1200HS3, WG1900HP2, WG1200HP3, WG1800HP3, WG1200HS2, WG1900HP, WG1200HP2, W1200EX(-MS), WG1200HS, WG1200HP, WF300HP2,. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A vulnerability was found in Tenda FH1205 2.0.0.7(775). Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability was found in Tenda FH1205 2.0.0.7(775). Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability was found in Tenda FH1205 2.0.0.7(775) and classified as critical. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability, which was classified as critical, was found in Tenda FH1205 2.0.0.7(775). Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability, which was classified as critical, has been found in Tenda FH1205 2.0.0.7(775). Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability classified as critical was found in Tenda FH1205 2.0.0.7(775). Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
NVIDIA GPU Display Driver for Windows contains a vulnerability in the user mode layer, where an unprivileged regular user can cause an out-of-bounds write. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
A vulnerability was found in Tenda FH1203 2.0.1.6. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability was found in Tenda FH1203 2.0.1.6. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability was found in Tenda FH1203 2.0.1.6 and classified as critical. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability, which was classified as critical, was found in Tenda FH1203 2.0.1.6. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability, which was classified as critical, has been found in Tenda FH1203 2.0.1.6. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability classified as critical was found in Tenda FH1203 2.0.1.6. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability in the IKEv1 fragmentation code of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a heap underflow, resulting in an affected. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A vulnerability in the IKEv1 fragmentation code of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a heap overflow, resulting in an affected. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A vulnerability classified as critical has been found in Tenda FH1202 1.2.0.14(408). Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability was found in Tenda FH1202 1.2.0.14(408). Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability was found in Tenda FH1202 1.2.0.14(408). Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability in the DHCP snooping feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload unexpectedly, resulting in a denial of. Rated high severity (CVSS 8.6), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A vulnerability was found in Tenda FH1202 1.2.0.14(408). Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability was found in Tenda FH1202 1.2.0.14(408) and classified as critical. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability, which was classified as critical, was found in Tenda FH1202 1.2.0.14(408). Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability, which was classified as critical, has been found in Tenda FH1202 1.2.0.14(408). Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability classified as critical was found in Tenda F1203 2.0.1.6. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability classified as critical has been found in Tenda F1203 2.0.1.6. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability was found in Tenda F1203 2.0.1.6. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
A vulnerability was found in Tenda F1203 2.0.1.6. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
An issue was discovered in gui/util/qktxhandler.cpp in Qt before 5.15.17, 6.x before 6.2.12, 6.3.x through 6.5.x before 6.5.5, and 6.6.x before 6.6.2. Rated medium severity (CVSS 6.2), this vulnerability is no authentication required, low attack complexity. This Buffer Copy without Size Check vulnerability could allow attackers to overflow a buffer to corrupt adjacent memory.