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 (5472)
Vulnerability in the PeopleSoft Enterprise PeopleTools product of Oracle PeopleSoft (component: Panel Processor). Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Linksys E8450 v1.2.00.360516 was discovered to contain a buffer overflow vulnerability. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. Public exploit code available and no vendor patch available.
Linksys E8450 v1.2.00.360516 was discovered to contain a buffer overflow vulnerability. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. Public exploit code available and no vendor patch available.
Linksys E8450 v1.2.00.360516 was discovered to contain a buffer overflow vulnerability. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. Public exploit code available and no vendor patch available.
Linksys E8450 v1.2.00.360516 was discovered to contain a buffer overflow vulnerability. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. Public exploit code available and no vendor patch available.
Linksys E8450 v1.2.00.360516 was discovered to contain a buffer overflow vulnerability. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Linksys E8450 v1.2.00.360516 was discovered to contain a buffer overflow vulnerability. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Linksys E8450 v1.2.00.360516 was discovered to contain a buffer overflow vulnerability. Rated medium severity (CVSS 6.3), this vulnerability is no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
In the Linux kernel, the following vulnerability has been resolved: riscv: mm: Fix the out of bound issue of vmemmap address In sparse vmemmap model, the virtual address of vmemmap is calculated as:. Rated high severity (CVSS 7.1), this vulnerability is low attack complexity. This Out-of-bounds Read vulnerability could allow attackers to read data from memory outside the intended buffer boundaries.
In the Linux kernel, the following vulnerability has been resolved: net/sctp: Prevent autoclose integer overflow in sctp_association_init() While by default max_autoclose equals to INT_MAX / HZ, one. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity.
Vim is an open source, command line text editor. Rated medium severity (CVSS 4.2). This Out-of-bounds Write vulnerability could allow attackers to write data beyond allocated buffer boundaries leading to code execution or crashes.
In the Linux kernel, the following vulnerability has been resolved: netfs: Fix enomem handling in buffered reads If netfs_read_to_pagecache() gets an error from either ->prepare_read() or from. Rated high severity (CVSS 7.1), this vulnerability is low attack complexity. This Out-of-bounds Read vulnerability could allow attackers to read data from memory outside the intended buffer boundaries.
In the Linux kernel, the following vulnerability has been resolved: net_sched: cls_flow: validate TCA_FLOW_RSHIFT attribute syzbot found that TCA_FLOW_RSHIFT attribute was not validated. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity.
In the Linux kernel, the following vulnerability has been resolved: net: hns3: fixed hclge_fetch_pf_reg accesses bar space out of bounds issue The TQP BAR space is divided into two segments. 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.
In the Linux kernel, the following vulnerability has been resolved: sched: sch_cake: add bounds checks to host bulk flow fairness counts Even though we fixed a logic error in the commit cited below,. Rated high severity (CVSS 7.1), this vulnerability is low attack complexity. This Out-of-bounds Read vulnerability could allow attackers to read data from memory outside the intended buffer boundaries.
A vulnerability classified as critical has been found in Tenda AC15 15.13.07.13. Rated high severity (CVSS 8.7), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and EPSS exploitation probability 10.2%.
A vulnerability, which was classified as critical, was found in code-projects Train Ticket Reservation System 1.0. Rated medium severity (CVSS 4.8), this vulnerability is low attack complexity. Public exploit code available and no vendor patch available.
Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') vulnerability in Newtec NTC2218, NTC2250, NTC2299 on Linux, PowerPC, ARM (Updating signaling process in the swdownload binary. Rated critical severity (CVSS 9.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
could allow an unauthorized attacker to modify configuration values outside of the normal range when the attacker sends specific Modbus write packets to the device which could result in invalid data. Rated medium severity (CVSS 6.9), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
could allow local attackers to exploit these issues to potentially execute arbitrary code when opening a malicious project file. Rated medium severity (CVSS 4.6), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Fuji Electric Alpha5 SMART is vulnerable to a stack-based buffer overflow, which may allow an attacker to execute arbitrary code. Rated high severity (CVSS 8.5), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Tenda AC8v4 V16.03.34.06 has a stack overflow vulnerability. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.
Tenda AC8v4 V16.03.34.06 has a stack overflow vulnerability. 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 AC18 V15.03.05.19 was discovered to contain a stack overflow via the startIP parameter in the formSetPPTPServer 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 AC18 V15.03.05.19 was discovered to contain a stack overflow via the firewallEn parameter in the formSetFirewallCfg 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 AC18 V15.03.05.19 was discovered to contain a stack overflow via the devName parameter in 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 AC18 V15.03.05.19 was discovered to contain a stack overflow via the limitSpeedUp parameter in the formSetClientState function. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Tenda AC18 V15.03.05.19 was discovered to contain a stack overflow via the funcpara1 parameter in the formSetCfm 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 AC18 V15.03.05.19 was discovered to contain a stack overflow via the speed_dir parameter in the formSetSpeedWan function. Rated medium severity (CVSS 5.7), this vulnerability is low attack complexity. No vendor patch available.
Tenda AC18 V15.03.05.19 was discovered to contain a stack overflow via the ssid parameter in the form_fast_setting_wifi_set function. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Unchecked Return Value, Out-of-bounds Read vulnerability in FFmpeg allows Read Sensitive Constants Within an Executable. Rated medium severity (CVSS 4.8), this vulnerability is remotely exploitable, low attack complexity.
RE11S v1.11 was discovered to contain a stack overflow via the pppUserName parameter in the formPPPoESetup 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.
RE11S v1.11 was discovered to contain a stack overflow via the rootAPmac parameter in the formStaDrvSetup 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.
RE11S v1.11 was discovered to contain a stack overflow via the selSSID parameter in the formWlSiteSurvey 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.
RE11S v1.11 was discovered to contain a stack overflow via the pptpUserName parameter in the setWAN 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 heap-based buffer overflow flaw was found in the rsync daemon. 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.
In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: fix mbss changed flags corruption on 32 bit systems On 32-bit systems, the size of an unsigned long is 4 bytes,. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity.
In the Linux kernel, the following vulnerability has been resolved: ALSA: seq: oss: Fix races at processing SysEx messages OSS sequencer handles the SysEx messages split in 6 bytes packets, and ALSA. Rated medium severity (CVSS 6.3).
In the Linux kernel, the following vulnerability has been resolved: RDMA/uverbs: Prevent integer overflow issue In the expression "cmd.wqe_size * cmd.wr_count", both variables are u32 values that. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity.
In the Linux kernel, the following vulnerability has been resolved: nvmet: Don't overflow subsysnqn nvmet_root_discovery_nqn_store treats the subsysnqn string like a fixed size buffer, even though it. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. This Buffer Copy without Size Check vulnerability could allow attackers to overflow a buffer to corrupt adjacent memory.
Stack buffer overflow in Tracing in Google Chrome prior to 132.0.6834.83 allowed a remote attacker to potentially exploit stack corruption via a crafted HTML page. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Out of bounds read in Metrics in Google Chrome prior to 132.0.6834.83 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Integer overflow in Skia in Google Chrome prior to 132.0.6834.83 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page. 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.
Out of bounds memory access in V8 in Google Chrome prior to 132.0.6834.83 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page. 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.
Stack-based buffer overflow vulnerability exists in Linux Ratfor 1.06 and earlier. Rated high severity (CVSS 7.0), this vulnerability is no authentication required. No vendor patch available.
Tenda i24 V2.0.0.5 is vulnerable to Buffer Overflow in the addWifiMacFilter function. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
H3C N12 V100R005 contains a buffer overflow vulnerability due to the lack of length verification in the mac address editing function. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
H3C N12 V100R005 contains a buffer overflow vulnerability due to the lack of length verification in the 5G wireless network processing function. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
H3C N12 V100R005 contains a buffer overflow vulnerability due to the lack of length verification in the AP configuration function. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
H3C N12 V100R005 contains a buffer overflow vulnerability due to the lack of length verification in the mac address update function. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
H3C N12 V100R005 contains a buffer overflow vulnerability due to the lack of length verification in the 2.4G wireless network processing function. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A potential buffer overflow vulnerability was reported in PC Manager, Lenovo Browser, and Lenovo App Store that could allow a local attacker to cause a system crash. Rated medium severity (CVSS 4.7). No vendor patch available.
A potential TOCTOU vulnerability was reported in PC Manager, Lenovo Browser, and Lenovo App Store that could allow a local attacker to cause a system crash. Rated medium severity (CVSS 4.7). No vendor patch available.
Substance3D - Designer versions 14.0 and earlier are affected by a Heap-based Buffer Overflow vulnerability that could result in arbitrary code execution in the context of the current user. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Substance3D - Designer versions 14.0 and earlier are affected by an out-of-bounds write vulnerability that could result in arbitrary code execution in the context of the current user. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Substance3D - Designer versions 14.0 and earlier are affected by a Heap-based Buffer Overflow vulnerability that could result in arbitrary code execution in the context of the current user. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Substance3D - Designer versions 14.0 and earlier are affected by an out-of-bounds write vulnerability that could result in arbitrary code execution in the context of the current user. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Substance3D - Stager versions 3.0.4 and earlier are affected by an out-of-bounds write vulnerability that could result in arbitrary code execution in the context of the current user. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Substance3D - Stager versions 3.0.4 and earlier are affected by an out-of-bounds write vulnerability that could result in arbitrary code execution in the context of the current user. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Substance3D - Stager versions 3.0.4 and earlier are affected by an out-of-bounds write vulnerability that could result in arbitrary code execution in the context of the current user. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Substance3D - Stager versions 3.0.4 and earlier are affected by a Heap-based Buffer Overflow vulnerability that could result in arbitrary code execution in the context of the current user. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Substance3D - Stager versions 3.0.4 and earlier are affected by a Stack-based Buffer Overflow vulnerability that could result in arbitrary code execution in the context of the current user. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Out-of-bounds write in the PCX image codec in QNX SDP versions 8.0, 7.1 and 7.0 could allow an unauthenticated attacker to cause a denial-of-service condition or execute code in the context of the. 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 the TIFF image codec in QNX SDP versions 8.0, 7.1 and 7.0 could allow an unauthenticated attacker to cause an information disclosure in the context of the process using the. Rated medium severity (CVSS 5.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Windows Telephony Service Remote Code Execution Vulnerability. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
Windows Telephony Service Remote Code Execution Vulnerability. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
Windows Telephony Service Remote Code Execution Vulnerability. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
Windows Telephony Service Remote Code Execution Vulnerability. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
Microsoft Access Remote Code Execution Vulnerability. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity.
Windows Graphics Component Elevation of Privilege Vulnerability. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity.
Windows CSC Service Elevation of Privilege Vulnerability. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity.
Windows CSC Service Information Disclosure Vulnerability. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. This Out-of-bounds Read vulnerability could allow attackers to read data from memory outside the intended buffer boundaries.
Microsoft Office Visio Remote Code Execution Vulnerability. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity.
Windows Digital Media Elevation of Privilege Vulnerability. Rated medium severity (CVSS 6.6), this vulnerability is low attack complexity. This Out-of-bounds Read vulnerability could allow attackers to read data from memory outside the intended buffer boundaries.
Windows Telephony Service Remote Code Execution Vulnerability. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
Windows Hyper-V NT Kernel Integration VSP contains a heap-based buffer overflow allowing authorized local attackers to escalate privileges, one of three Hyper-V zero-days exploited in January 2025 Patch Tuesday.
Windows Digital Media Elevation of Privilege Vulnerability. Rated medium severity (CVSS 6.6), this vulnerability is low attack complexity. This Out-of-bounds Read vulnerability could allow attackers to read data from memory outside the intended buffer boundaries.
Windows Digital Media Elevation of Privilege Vulnerability. Rated medium severity (CVSS 6.6), this vulnerability is low attack complexity. This Out-of-bounds Read vulnerability could allow attackers to read data from memory outside the intended buffer boundaries.
Windows Digital Media Elevation of Privilege Vulnerability. Rated medium severity (CVSS 6.6), this vulnerability is low attack complexity. This Out-of-bounds Read vulnerability could allow attackers to read data from memory outside the intended buffer boundaries.
Windows Telephony Service Remote Code Execution Vulnerability. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
Windows Telephony Service Remote Code Execution Vulnerability. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
Windows Telephony Service Remote Code Execution Vulnerability. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
Windows Telephony Service Remote Code Execution Vulnerability. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
Windows Telephony Service Remote Code Execution Vulnerability. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
Windows Telephony Service Remote Code Execution Vulnerability. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
Microsoft Message Queuing (MSMQ) Denial of Service Vulnerability. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Epss exploitation probability 30.3%.
Windows Telephony Service Remote Code Execution Vulnerability. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
Windows Cloud Files Mini Filter Driver Elevation of Privilege Vulnerability. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity.
Windows Telephony Service Remote Code Execution Vulnerability. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
Windows Digital Media Elevation of Privilege Vulnerability. Rated medium severity (CVSS 6.6), this vulnerability is low attack complexity. This Out-of-bounds Read vulnerability could allow attackers to read data from memory outside the intended buffer boundaries.