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 (36676)
An issue was discovered in illumos before 2020-10-22, as used in OmniOS before r151030by, r151032ay, and r151034y and SmartOS before 20201022. 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.
Belkin LINKSYS WRT160NL 1.0.04.002_US_20130619 devices have a stack-based buffer overflow vulnerability because of sprintf in create_dir in mini_httpd. 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 Xen through 4.14.x allowing x86 PV guest OS users to gain guest OS privileges by modifying kernel memory contents, because invalidation of TLB entries is mishandled during. Rated medium severity (CVSS 5.3), 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.
Mozilla developers reported memory safety bugs present in Firefox 81. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Mozilla developers and community members reported memory safety bugs present in Firefox 81 and Firefox ESR 78.3. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A buffer overflow 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.
An out-of-bounds read was 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 write issue was addressed with improved bounds checking. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
A buffer overflow 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.
An out-of-bounds read was 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 write issue was addressed with improved bounds checking. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
A memory corruption issue was addressed with improved memory handling. Rated high severity (CVSS 7.1), this vulnerability is low attack complexity. No vendor patch available.
Multiple memory corruption issues were addressed with improved memory handling. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
A memory corruption issue was addressed with improved input validation. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
A memory corruption issue was addressed with improved memory handling. Rated high severity (CVSS 7.0). No vendor patch available.
A buffer overflow 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.
An out-of-bounds read was addressed with improved input validation. Rated high severity (CVSS 7.1), this vulnerability is low attack complexity. No vendor patch available.
A memory corruption issue was addressed with improved input validation. Rated critical severity (CVSS 9.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A buffer overflow was addressed with improved bounds checking. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A memory corruption issue was addressed with improved state management. 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 medium severity (CVSS 5.5), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
A memory corruption issue was 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 state management. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
A memory corruption issue was addressed with improved input validation. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
A buffer overflow 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.
A buffer overflow 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.
A buffer overflow 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.
A buffer overflow was addressed with improved bounds checking. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
An out-of-bounds write issue was addressed with improved bounds checking. 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 no authentication required, low attack complexity. No vendor patch available.
An out-of-bounds write issue was addressed with improved bounds checking. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
An out-of-bounds write issue was addressed with improved bounds checking. 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 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 write issue was addressed with improved bounds checking. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
An out-of-bounds write issue was addressed with improved bounds checking. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
A memory corruption issue was addressed with improved memory handling. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A memory corruption issue was addressed with improved 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 input validation. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An out-of-bounds read was addressed with improved input validation. Rated high severity (CVSS 7.1), this vulnerability is low attack complexity. No vendor patch available.
A memory corruption issue was addressed with improved validation. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
Adobe After Effects version 17.1.1 (and earlier) is affected by an out-of-bounds read vulnerability when parsing a crafted .aepx file, which could result in a read past the end of an allocated memory. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity.
In Tensorflow before version 2.4.0, when the `boxes` argument of `tf.image.crop_and_resize` has a very large value, the CPU kernel implementation receives it as a C++ `nan` floating point value. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
In Tensorflow before version 2.4.0, an attacker can pass an invalid `axis` value to `tf.quantization.quantize_and_dequantize`. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
Adobe Animate version 20.5 (and earlier) is affected by an out-of-bounds read vulnerability, which 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.
Adobe Animate version 20.5 (and earlier) is affected by an out-of-bounds read 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.
Adobe Animate version 20.5 (and earlier) is affected by a stack overflow vulnerability, which could lead to 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.
A vulnerability in the SSL/TLS inspection of Cisco Firepower Threat Defense (FTD) Software for Cisco Firepower 2100 Series firewalls could allow an unauthenticated, remote attacker to cause a denial. Rated high severity (CVSS 8.6), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Vulnerability in the Oracle Solaris product of Oracle Systems (component: Pluggable authentication module). Rated critical severity (CVSS 10.0), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
Adobe Illustrator version 24.1.2 (and earlier) is affected by a memory corruption vulnerability that occurs when parsing a specially crafted .svg file. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity.
Adobe Illustrator version 24.1.2 (and earlier) is affected by a memory corruption vulnerability that occurs when parsing a specially crafted .svg file. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity.
Adobe Illustrator version 24.1.2 (and earlier) is affected by a memory corruption vulnerability that occurs when parsing a specially crafted .svg file. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity.
Adobe Illustrator version 24.1.2 (and earlier) is affected by a memory corruption vulnerability that occurs when parsing a specially crafted .svg file. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity.
Adobe Illustrator version 24.2 (and earlier) is affected by an out-of-bounds write vulnerability when handling crafted PDF files. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity.
Adobe Illustrator version 24.2 (and earlier) is affected by an out-of-bounds read vulnerability when parsing crafted PDF files. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity.
Adobe Illustrator version 24.2 (and earlier) is affected by an out-of-bounds read vulnerability when parsing crafted PDF files. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity.
VMware ESXi (7.0 before ESXi_7.0.1-0.0.16850804, 6.7 before ESXi670-202008101-SG, 6.5 before ESXi650-202007101-SG), Workstation (15.x), Fusion (11.x before 11.5.6) contain an out-of-bounds write. Rated high severity (CVSS 7.7), this vulnerability is remotely exploitable.
VMware ESXi (7.0 before ESXi_7.0.1-0.0.16850804, 6.7 before ESXi670-202008101-SG, 6.5 before ESXi650-202007101-SG), Workstation (15.x), Fusion (11.x before 11.5.6) contain an out-of-bounds read. Rated medium severity (CVSS 5.8), this vulnerability is remotely exploitable.
An exploitable denial of service vulnerability exists in the ENIP Request Path Logical Segment functionality of Allen-Bradley Flex IO 1794-AENT/B 4.003. 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.
An exploitable denial of service vulnerability exists in the ENIP Request Path Logical Segment functionality of Allen-Bradley Flex IO 1794-AENT/B 4.003. 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.
HUAWEI Mate 20 versions earlier than 10.0.0.188(C00E74R3P8) have a buffer overflow vulnerability in the Bluetooth module. Rated high severity (CVSS 8.0), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
An issue was discovered in the yh_create_session() function of yubihsm-shell through 2.0.2. 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.
A tftpserver stack-based buffer overflow remote code execution vulnerability was discovered in HPE Intelligent Management Center (iMC) version(s): Prior to iMC PLAT 7.3 (E0705P07). Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
GoPro gpmf-parser 1.5 has a heap out-of-bounds read and segfault in GPMF_ScaledData(). Rated critical severity (CVSS 9.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
GoPro gpmf-parser through 1.5 has a stack out-of-bounds write vulnerability in GPMF_ExpandComplexTYPE(). 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.
An issue was discovered in tcpreplay tcpprep v4.3.3. 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.
An issue was discovered in tcpreplay tcpprep v4.3.3. 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.
<p>A remote code execution vulnerability exists when the Base3D rendering engine improperly handles memory.</p> <p>An attacker who successfully exploited the vulnerability would gain execution on a. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. Epss exploitation probability 12.5%.
<p>A remote code execution vulnerability exists in Microsoft Outlook software when the software fails to properly handle objects in memory. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required. This Out-of-bounds Read vulnerability could allow attackers to read data from memory outside the intended buffer boundaries.
<p>A remote code execution vulnerability exists in Microsoft Excel software when the software fails to properly handle objects in memory. Rated high severity (CVSS 7.8), this vulnerability is 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.
<p>A remote code execution vulnerability exists when the Base3D rendering engine improperly handles memory.</p> <p>An attacker who successfully exploited the vulnerability would gain execution on a. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. Epss exploitation probability 12.5%.
<p>A memory corruption vulnerability exists when Windows Media Foundation improperly handles objects in memory. Rated high severity (CVSS 7.8), this vulnerability is 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.
On Juniper Networks Junos OS platforms configured as DHCPv6 local server or DHCPv6 Relay Agent, Juniper Networks Dynamic Host Configuration Protocol Daemon (JDHCPD) process might crash with a core. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A stack buffer overflow vulnerability in the device control daemon (DCD) on Juniper Networks Junos OS allows a low privilege local user to create a Denial of Service (DoS) against the daemon or. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
An out-of-bounds write issue was addressed with improved bounds checking. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An out-of-bounds write issue was addressed with improved bounds checking. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
An out-of-bounds write issue was addressed with improved bounds checking. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
A memory corruption 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.
An out-of-bounds read was addressed with improved input validation. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An out-of-bounds read was addressed with improved bounds checking. Rated medium severity (CVSS 5.9), this vulnerability is remotely exploitable, no authentication required. No vendor patch available.
A memory corruption issue was addressed by removing the vulnerable 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 was addressed with improved input validation. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
An out-of-bounds read was addressed with improved bounds checking. Rated 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 no authentication required, low attack complexity. No vendor patch available.
An out-of-bounds write issue was addressed with improved bounds checking. 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 no authentication required, low attack complexity. No vendor patch available.
An out-of-bounds write issue was addressed with improved bounds checking. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
A buffer overflow 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.
A memory corruption issue was addressed by removing the vulnerable code. Rated high severity (CVSS 8.6), 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 no authentication required, low attack complexity. No vendor patch available.
Crossbeam is a set of tools for concurrent programming. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.