Heap Overflow
A heap overflow occurs when a program writes data beyond the bounds of a buffer allocated in the heap memory region.
How It Works
A heap overflow occurs when a program writes data beyond the bounds of a buffer allocated in the heap memory region. Unlike stack overflows that target the call stack, heap overflows corrupt dynamically allocated memory managed by functions like malloc() or new. When a program allocates heap memory without properly validating input size, an attacker can supply excessive data that spills into adjacent heap chunks, corrupting heap metadata structures or neighboring objects.
Exploitation typically targets heap management metadata (chunk headers containing size and status information) or data in adjacent allocations. Attackers can overwrite function pointers stored in heap objects, C++ vtable pointers, or critical data fields to redirect program execution. Modern heap implementations use inline metadata, making them vulnerable to carefully crafted overflows that manipulate allocation structures to achieve arbitrary write primitives.
The attack difficulty varies by heap implementation. Attackers must understand the specific allocator's layout (glibc malloc, Windows heap, etc.) and often need information leaks to defeat ASLR. Heap feng shui techniques arrange heap allocations in predictable patterns, placing attacker-controlled data adjacent to target objects to maximize exploitation reliability.
Impact
- Arbitrary code execution: Overwrite function pointers or vtables to redirect control flow to attacker-supplied shellcode
- Memory corruption: Corrupt critical data structures, causing crashes or logic manipulation to bypass security checks
- Privilege escalation: Modify authorization flags or user context stored in heap objects
- Information disclosure: Trigger controlled crashes that leak sensitive data through error messages or core dumps
- Heap spray payloads: Combined with other vulnerabilities, create reliable exploitation paths across multiple platforms
Real-World Examples
The WhatsApp video call vulnerability (CVE-2019-11931) exploited a heap overflow in video decoding, allowing remote code execution through a malicious video file without user interaction. Attackers could compromise devices by simply calling targets.
The OpenSSL Heartbleed bug (CVE-2014-0160), while primarily an information disclosure issue, demonstrated heap-related vulnerabilities by allowing attackers to read arbitrary heap memory. Similar heap overflow issues in TLS implementations have enabled complete server compromise.
The sudo heap overflow (CVE-2021-3156) allowed local privilege escalation on Unix systems by overflowing a heap buffer through carefully crafted command-line arguments, giving unprivileged users root access on affected systems.
Mitigation
- Memory-safe languages: Use Rust, Go, or managed languages that eliminate manual memory management vulnerabilities
- Hardened heap allocators: Deploy jemalloc, PartitionAlloc, or Scudo with guard pages and randomization features
- Address Space Layout Randomization (ASLR): Randomize heap base addresses to make exploitation non-deterministic
- Bounds checking: Validate all input sizes before heap operations and use safe string functions (
strncpy,snprintf) - Heap integrity checks: Enable heap consistency verification in production environments
- Compiler mitigations: Use AddressSanitizer during development and fortify source options at compile time
- Size limits: Enforce maximum allocation sizes and reject excessive input
Recent CVEs (1938)
Sonos Era 300 Heap-based Buffer Overflow Remote Code Execution Vulnerability. Rated high severity (CVSS 8.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Luxion KeyShot Viewer KSP File Parsing Heap-based Buffer Overflow Remote Code Execution Vulnerability. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Heap buffer overflow in Codecs in Google Chrome on Windows prior to 135.0.7049.95 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.
A maliciously crafted DWG file, when parsed through Autodesk Revit, can cause a Stack-Based Buffer Overflow vulnerability. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
A maliciously crafted PDF file, when linked or imported into Autodesk applications, can force a Heap-Based Overflow vulnerability. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
A maliciously crafted JPG file, when linked or imported into certain Autodesk applications, can force a Heap-Based Overflow vulnerability. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
A maliciously crafted PDF file, when linked or imported into Autodesk applications, can force a Heap-Based Overflow vulnerability. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
An integer overflow can be triggered in SQLite’s `concat_ws()` function. Rated medium severity (CVSS 6.9), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
Heap-based Buffer Overflow vulnerability in openEuler giflib on Linux. Rated high severity (CVSS 7.3), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
A heap buffer overflow vulnerability was discovered in Perl. Rated high severity (CVSS 8.4), this vulnerability is no authentication required, low attack complexity.
There is a Heap-based Buffer Overflow vulnerability in QTextMarkdownImporter. Rated medium severity (CVSS 4.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
A Heap-based Buffer Overflow vulnerability in the flexible PIC concentrator (FPC) of Juniper Networks Junos OS on EX2300, EX3400, EX4100, EX4300, EX4300MP, EX4400, EX4600, EX4650-48Y, and QFX5k. Rated high severity (CVSS 7.7), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Adobe Framemaker versions 2020.8, 2022.6 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.
Adobe Framemaker versions 2020.8, 2022.6 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.
Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to execute code locally. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Heap-based buffer overflow in Windows Bluetooth Service allows an authorized attacker to elevate privileges locally. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
Heap-based buffer overflow in Remote Desktop Client allows an authorized attacker to execute code over a network. Rated high severity (CVSS 8.0), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Heap-based buffer overflow in Windows Local Security Authority (LSA) allows an authorized attacker to elevate privileges locally. Rated high severity (CVSS 7.0). No vendor patch available.
Heap-based buffer overflow in Windows Telephony Service allows an unauthorized attacker to execute code over a network. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Animate versions 24.0.7, 23.0.10 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.
Photoshop Desktop versions 25.12.1, 26.4.1 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.
Premiere Pro versions 25.1, 24.6.4 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.
Media Encoder versions 25.1, 24.6.4 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.
Bridge versions 14.1.5, 15.0.2 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.
Heap-based buffer overflow in Windows Media allows an authorized attacker to execute code locally. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
Heap-based buffer overflow in Windows Routing and Remote Access Service (RRAS) allows an unauthorized attacker to execute code over a network. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required. No vendor patch available.
Heap-based buffer overflow in Windows Media allows an authorized attacker to execute code locally. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
Integer overflow or wraparound in Windows USB Print Driver allows an authorized attacker to elevate privileges locally. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. No vendor patch available.
Heap-based buffer overflow in Windows Telephony Service allows an unauthorized attacker to execute code over a network. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Heap-based buffer overflow in Windows Telephony Service allows an unauthorized attacker to execute code over a network. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Heap-based buffer overflow in Windows Telephony Service allows an unauthorized attacker to execute code over a network. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
libvips is a demand-driven, horizontally threaded image processing library. Rated high severity (CVSS 8.5), this vulnerability is low attack complexity. Public exploit code available.
A heap buffer overflow vulnerability has been identified in thesmooth2() in cmsgamma.c in lcms2-2.16 which allows a remote attacker to cause a denial of service. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A heap buffer overflow vulnerability has been identified in the lcms2-2.16. Rated high severity (CVSS 7.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
heap-buffer overflow in fig2dev in version 3.2.9a allows an attacker to availability via local input manipulation via create_line_with_spline. Rated medium severity (CVSS 6.6), this vulnerability is low attack complexity. Public exploit code available and no vendor patch available.
CryptoLib provides a software-only solution using the CCSDS Space Data Link Security Protocol - Extended Procedures (SDLS-EP) to secure communications between a spacecraft running the core Flight. Rated critical severity (CVSS 9.4), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
Luxion KeyShot DAE File Parsing Heap-based Buffer Overflow Remote Code Execution Vulnerability. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
The various bson_append functions in the MongoDB C driver library may be susceptible to buffer overflow when performing operations that could result in a final BSON document which exceeds the maximum. Rated high severity (CVSS 8.4), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
CryptoLib provides a software-only solution using the CCSDS Space Data Link Security Protocol - Extended Procedures (SDLS-EP) to secure communications between a spacecraft running the core Flight. Rated high severity (CVSS 8.9), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
CryptoLib provides a software-only solution using the CCSDS Space Data Link Security Protocol - Extended Procedures (SDLS-EP) to secure communications between a spacecraft running the core Flight. Rated high severity (CVSS 8.9), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.
A maliciously crafted MODEL file, when parsed through Autodesk AutoCAD, can force a Heap-Based Overflow vulnerability. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
A maliciously crafted MODEL file, when parsed through Autodesk AutoCAD, can force a Heap-Based Overflow vulnerability. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
An out-of-bounds write vulnerability exists in the ma_dr_flac__decode_samples__lpc functionality of Miniaudio miniaudio v0.11.21. Rated high severity (CVSS 7.7), this vulnerability is remotely exploitable, no authentication required. Public exploit code available and no vendor patch available.
Memory safety bugs present in Firefox 135 and Thunderbird 135. Rated high severity (CVSS 8.2), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Delta Electronics CNCSoft-G2 lacks proper validation of the length of user-supplied data prior to copying it to a fixed-length heap-based buffer. Rated high severity (CVSS 8.4), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Buffer overflow in some Zoom Workplace Apps and SDKs may allow an authenticated user to conduct a denial of service via network access. Rated medium severity (CVSS 4.3), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
Buffer overflow in some Zoom Apps may allow an authenticated user to conduct an escalation of privilege via network access. Rated high severity (CVSS 8.5), this vulnerability is remotely exploitable. No vendor patch available.
OpenH264 is a free license codec library which supports H.264 encoding and decoding. Rated high severity (CVSS 8.6), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Heap buffer overflow in GPU in Google Chrome on Android prior to 133.0.6943.126 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.
Heap buffer overflow in V8 in Google Chrome prior to 133.0.6943.126 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.
Heap-based Buffer Overflow vulnerability in iniparser_dumpsection_ini() in iniparser allows attacker to read out of bound memory. Rated medium severity (CVSS 5.1), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
A heap buffer overflow vulnerability in FFmpeg before commit 4bf784c allows attackers to trigger a memory corruption via supplying a crafted media file in avformat when processing tile grid group. Rated medium severity (CVSS 5.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A Structured Exception Handler based buffer overflow vulnerability exists in Effectmatrix Total Video Converter Command Line (TVCC) 2.50 when a specially crafted file is passed to the -ff parameter. Rated medium severity (CVSS 5.5), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
An issue was discovered in Mercedes Benz NTG (New Telematics Generation) 6. Rated medium severity (CVSS 4.6), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
Heap-based buffer overflow in BMC Firmware for the Intel(R) Server Board S2600WF, Intel(R) Server Board S2600ST, Intel(R) Server Board S2600BP, before version 02.01.0017 and Intel(R) Server Board. Rated high severity (CVSS 8.4), this vulnerability is low attack complexity. No vendor patch available.
NVIDIA nvJPEG2000 library contains a vulnerability where an attacker can cause a heap-based buffer overflow issue by means of a specially crafted JPEG2000 file. Rated medium severity (CVSS 6.8), this vulnerability is remotely exploitable, no authentication required. No vendor patch available.
Mintty Sixel Image Parsing Heap-based Buffer Overflow Remote Code Execution Vulnerability. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
PDF-XChange Editor RTF File Parsing Heap-based Buffer Overflow Remote Code Execution Vulnerability. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
Windows Ancillary Function Driver for WinSock contains a heap-based buffer overflow enabling local privilege escalation to SYSTEM, exploited in the wild in February 2025.
Windows Core Messaging Elevation of Privileges Vulnerability. Rated high severity (CVSS 7.0).
Windows Routing and Remote Access Service (RRAS) 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 Excel Remote Code Execution Vulnerability. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity.
Windows Lightweight Directory Access Protocol (LDAP) Remote Code Execution Vulnerability. Rated high severity (CVSS 8.1), this vulnerability is remotely exploitable, no authentication required.
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 Digest Authentication Remote Code Execution Vulnerability. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity.
Microsoft Digest Authentication Remote Code Execution Vulnerability. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity.
Windows Routing and Remote Access Service (RRAS) 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 Core Messaging Elevation of Privileges Vulnerability. Rated high severity (CVSS 7.0).
InDesign Desktop versions ID20.0, ID19.5.1 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.
Delta Electronics CNCSoft-G2 lacks proper validation of the length of user-supplied data prior to copying it to a fixed-length heap-based buffer. Rated high severity (CVSS 7.8), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
In Ashlar-Vellum Cobalt versions prior to v12 SP2 Build (1204.200), the affected application lacks proper validation of user-supplied data when parsing CO files. Rated high severity (CVSS 8.4), this vulnerability is no authentication required, low attack complexity. No vendor patch available.
In some cases, the ktrace facility will log the contents of kernel structures to userspace. Rated medium severity (CVSS 4.9), this vulnerability is remotely exploitable, low attack complexity. No vendor patch available.
SunGrow WiNet-SV200.001.00.P027 and earlier versions is vulnerable to heap-based buffer overflow due to bounds checks of the MQTT message content. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
LibVNCServer 0.9.12 release and earlier contains heap buffer overflow vulnerability within the HandleCursorShape() function in libvncclient/cursor.c. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
Object corruption in V8 in Google Chrome prior to 132.0.6834.110 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page. Rated high severity (CVSS 8.2), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A vulnerability in the Object Linking and Embedding 2 (OLE2) decryption routine of ClamAV could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected. Rated medium severity (CVSS 5.3), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
A buffer overflow vulnerability has been identified in the Internet Printing Protocol (IPP) in various Lexmark devices. Rated high severity (CVSS 8.8), this vulnerability is no authentication required, low attack complexity. 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.
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.
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 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 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.
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.