Buffer Copy without Checking Size of Input
CWE-120
The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.
We track 2,043 vulnerabilities of this type. 100% are rated high or critical, and the average CVSS score is 8.6. 24 have been exploited in real attacks.
How this weakness is prevented
- Requirements: Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
- Architecture and Design: Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega, and the Strsafe.h library from Microsoft. These libraries provide safer versions of overflow-prone string-handling functions.
- Operation Build and Compilation: Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.
- Architecture and Design: For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
- Operation: Use a CPU and operating system that offers Data Execution Protection (using hardware NX or XD bits) or the equivalent techniques that simulate this feature in software, such as PaX. These techniques ensure that any instruction executed is exclusively at a memory address that is part of the code segment. For more information on these techniques see D3-PSEP (Process Segment Execution Prevention) from D3FEND.
Latest Buffer Copy without Checking Size of Input vulnerabilities
- 7.5 High severity
P110 v1: Buffer Copy without Checking Size of Input
Tapo P110 v1 smart Wi-Fi Plug contains an improper boundary validation vulnerability in the handling of authenticated HTTP request bodies due to insufficient input validation before memory copy operations. This may lead to buffer overflow condition, causing th
- 8.4 High severity
PowerVM Hypervisor: Buffer Copy without Checking Size of Input
IBM PowerVM Hypervisor FW1110.00 through FW1110.20, FW1060.00 through FW1060.71, and FW950.00 through FW950.H1 A carefully crafted OS hypervisor call can cause the PowerVM hypervisor to crash or compromise OS memory integrity.
- 9.8 Critical severity
macOS: Buffer Copy without Checking Size of Input
A buffer overflow was addressed with improved bounds checking. This issue is fixed in macOS Sequoia 15.7.8, macOS Sequoia 15.8.2, macOS Sonoma 14.8.8, macOS Tahoe 26.6. A remote attacker may be able to cause unexpected system termination or corrupt kernel memo
- 7.8 High severity
iOS and iPadOS: Buffer Copy without Checking Size of Input
A buffer overflow was addressed with improved size validation. This issue is fixed in iOS 18.7.10 and iPadOS 18.7.10, iOS 26.6 and iPadOS 26.6, macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, macOS Tahoe 26.6, tvOS 26.6, visionOS 26.6, watchOS 26.6. An app may be a
- 9.8 Critical severity
macOS: Buffer Copy without Checking Size of Input
A buffer overflow was addressed with improved size validation. This issue is fixed in macOS Tahoe 26.6. An app may be able to cause unexpected system termination.
- 9.8 Critical severity
iOS and iPadOS: Buffer Copy without Checking Size of Input
A buffer overflow was addressed with improved bounds checking. This issue is fixed in iOS 18.7.10 and iPadOS 18.7.10, iOS 26.5.2 and iPadOS 26.5.2, macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, macOS Tahoe 26.5.2, tvOS 26.6, visionOS 26.6, watchOS 26.6. A malicio
- 7.8 High severity
iOS and iPadOS: Buffer Copy without Checking Size of Input
A buffer overflow was addressed with improved bounds checking. This issue is fixed in iOS 18.7.10 and iPadOS 18.7.10, iOS 26.6 and iPadOS 26.6, macOS Sequoia 15.7.8, macOS Tahoe 26.6. Processing a maliciously crafted file may lead to unexpected app termination
- 9.8 Critical severity
macOS: Buffer Copy without Checking Size of Input
A buffer overflow was addressed with improved bounds checking. This issue is fixed in macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, macOS Tahoe 26.6. An app may be able to execute arbitrary code out of its sandbox or with certain elevated privileges.
- 7.1 High severity
macOS: Buffer Copy without Checking Size of Input
A buffer overflow was addressed with improved bounds checking. This issue is fixed in macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, macOS Tahoe 26.6. A local user may be able to read kernel memory.
- 7.8 High severity
macOS: Buffer Copy without Checking Size of Input
A buffer overflow was addressed with improved bounds checking. This issue is fixed in macOS Sequoia 15.7.8, macOS Sonoma 14.8.8, macOS Tahoe 26.6. Processing a maliciously crafted image may lead to arbitrary code execution.
- 8.8 High severity
iOS and iPadOS: Buffer Copy without Checking Size of Input
A buffer overflow was addressed with improved bounds checking. This issue is fixed in iOS 26.6 and iPadOS 26.6, macOS Tahoe 26.6, tvOS 26.6, watchOS 26.6. Connecting to a malicious NFS server may lead to kernel memory corruption.
- 8.3 High severity
OTP: Buffer Copy without Checking Size of Input
Classic buffer overflow in the Erlang/OTP megaco flex scanner C driver allows a remote unauthenticated attacker to corrupt the driver's memory (and potentially achieve remote code execution or a denial-of-service crash) by sending a single text-encoded H.248/M
- 7.5 High severity
Apache NimBLE: Buffer Copy without Checking Size of Input
Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') vulnerability in Apache NimBLE. The HCI socket transport did not check whether a received HCI event would fit the configured event pool before copying it, allowing a buffer overflow. Severi
- 7.2 High severity
AOS-CX: Buffer Copy without Checking Size of Input
Buffer overflow vulnerabilities exist in the command line interface of AOS-CX. Successful exploitation of these vulnerabilities could allow a remote high-privileged user to execute arbitrary code as a privileged user on the underlying operating system.
- 8.8 High severity
AOS-CX: Buffer Copy without Checking Size of Input
A buffer overflow vulnerability was found in the command line interface of AOS-CX. Successful exploitation of these vulnerabilities could allow an remote low-privileged user to execute arbitrary code as a privileged user on the underlying operating system.
- 9.8 Critical severity
Linux: Buffer Copy without Checking Size of Input
In the Linux kernel, the following vulnerability has been resolved: scsi: target: iscsi: Bound iscsi_encode_text_output() appends to rsp_buf iscsi_encode_text_output() concatenates "key=value\0" records into login->rsp_buf, an 8192-byte kzalloc(MAX_KEY_VALUE_P
- 7.5 High severity
quicly: Buffer Copy without Checking Size of Input
Quicly is an IETF QUIC protocol implementation intended primarily for use within the H2O HTTP server. Prior to commit 8b178e6, Quicly is vulnerable to a Denial of Service attack through connection state corruption. In QUIC Invariants, the maximum length of a C
- 9.2 Critical severity
CompactLogix® 5380 Recovery Image Compact…: Buffer Copy without Checking Size of Input
A denial-of-service issue exists in 5380/5480/5580 controllers boot firmware lower than version 1.072. This vulnerability could potentially allow a malicious user to write invalid file data to the controller, causing the device to enter a major non-recoverable
- 9.2 Critical severity
CompactLogix® 5370 Compact GuardLogix® 5370…: Buffer Copy without Checking Size of Input
A denial-of-service issue exists in 5380/5480/5580 controllers. This vulnerability could potentially allow a malicious user to write invalid file data to the controller, causing the device to enter a major non-recoverable fault (MNRF).
- 9.2 Critical severity
CompactLogix® 5370 Compact GuardLogix® 5370…: Buffer Copy without Checking Size of Input
A denial-of-service issue exists in 5370/5570 controllers. This vulnerability could potentially allow a remote user to load an invalid project, causing the device to enter a major non-recoverable fault (MNRF).
- 8.8 High severity
CH22: Improper Restriction of Operations within the Bounds of a Memory Buffer
A vulnerability was found in Tenda CH22 1.0.0.1. This impacts the function formCertListInfo of the file /goform/CertListInfo. The manipulation of the argument Name results in buffer overflow. The attack can be launched remotely. The exploit has been made publi
- 8.8 High severity
TEW-821DAP: Improper Restriction of Operations within the Bounds of a Memory Buffer
A vulnerability was detected in TRENDnet TEW-821DAP 1.12B01. The affected element is the function sub_41EC14 of the file /goform/tools_nslookup of the component ssi. The manipulation results in buffer overflow. It is possible to launch the attack remotely. The
- 8.8 High severity
TEW-821DAP: Improper Restriction of Operations within the Bounds of a Memory Buffer
A security vulnerability has been detected in TRENDnet TEW-821DAP 1.12B01. Impacted is the function sub_41EC14 of the file /goform/tools_nslookup of the component ssi. The manipulation of the argument nslookup_target leads to buffer overflow. It is possible to
- 9.8 Critical severity
u-boot: Buffer Copy without Checking Size of Input
U-Boot before 2026.07-rc2 contains a buffer overflow vulnerability in nfs_readlink_reply() (net/nfs-common.c) when CONFIG_CMD_NFS is enabled, allowing a malicious or compromised NFS server to overflow the 2048-byte nfs_path_buff buffer by returning multiple re
- 7.8 High severity
Foxit PDF Editor: Buffer Copy without Checking Size of Input
When dealing with abnormally constructed objects, there is a lack of argument validation; JavaScript triggers signature verification, but the signature plugin does not perform validation when copying the abnormal string, causing the application to crash.
- 8.8 High severity
Fireware OS: Out-of-bounds Write
An Out-of-bounds Write vulnerability in WatchGuard Fireware OS may allow an unauthenticated attacker on the same local network segment to execute arbitrary code. This vulnerability affects Fireware OS 11.0 up to and including 11.12.4_Update1, 12.0 up to and in
- 8.3 High severity
GeoWebPlayer: Buffer Copy without Checking Size of Input
GeoWebPlayer (also called "Web Plugin" in the GV-VMS documentation and "WS Player" for VMS-Cloud) is an addon that can be installed with various GeoVision software (GV-VMS, GV-Cloud, ...). It creates a websocket server that expands the capabilities of the vari
- 8.3 High severity
GeoWebPlayer: Buffer Copy without Checking Size of Input
GeoWebPlayer (also called "Web Plugin" in the GV-VMS documentation and "WS Player" for VMS-Cloud) is an addon that can be installed with various GeoVision software (GV-VMS, GV-Cloud, ...). It creates a websocket server that expands the capabilities of the vari
- 8.3 High severity
GeoWebPlayer: Buffer Copy without Checking Size of Input
GeoWebPlayer (also called "Web Plugin" in the GV-VMS documentation and "WS Player" for VMS-Cloud) is an addon that can be installed with various GeoVision software (GV-VMS, GV-Cloud, ...). It creates a websocket server that expands the capabilities of the vari
- 8.3 High severity
GeoWebPlayer: Buffer Copy without Checking Size of Input
GeoWebPlayer (also called "Web Plugin" in the GV-VMS documentation and "WS Player" for VMS-Cloud) is an addon that can be installed with various GeoVision software (GV-VMS, GV-Cloud, ...). It creates a websocket server that expands the capabilities of the vari
- 8.3 High severity
GeoWebPlayer: Buffer Copy without Checking Size of Input
GeoWebPlayer (also called "Web Plugin" in the GV-VMS documentation and "WS Player" for VMS-Cloud) is an addon that can be installed with various GeoVision software (GV-VMS, GV-Cloud, ...). It creates a websocket server that expands the capabilities of the vari
- 8.3 High severity
GeoWebPlayer: Buffer Copy without Checking Size of Input
GeoWebPlayer (also called "Web Plugin" in the GV-VMS documentation and "WS Player" for VMS-Cloud) is an addon that can be installed with various GeoVision software (GV-VMS, GV-Cloud, ...). It creates a websocket server that expands the capabilities of the vari
- 7.5 High severity
Cisco Secure Endpoint: Buffer Copy without Checking Size of Input
A vulnerability in the DMG file format parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition, or possibly other expanded impacts, resulting from memory corruption on an affected device. This vulnerability is due to improper
- 7.5 High severity
Cisco Secure Endpoint: Buffer Copy without Checking Size of Input
A vulnerability in the ALZ file format parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition, or possibly other expanded impacts, resulting from memory corruption on an affected device. This vulnerability is due to improper
- 7.5 High severity
Cisco Secure Endpoint: Buffer Copy without Checking Size of Input
A vulnerability in the PESpin file format parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition, or possibly other expanded impacts, resulting from memory corruption on an affected device. This vulnerability is due to improp
- 7.5 High severity
Cisco Secure Endpoint: Buffer Copy without Checking Size of Input
A vulnerability in the 7z file format parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition, or possibly other expanded impacts, resulting from memory corruption on an affected device. This vulnerability is due to improper b
- 7.5 High severity
Cisco Secure Endpoint: Buffer Copy without Checking Size of Input
A vulnerability in the FSG file format parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition, or possibly other expanded impacts, resulting from memory corruption on an affected device. This vulnerability is due to improper
- 7.5 High severity
Cisco Secure Endpoint: Buffer Copy without Checking Size of Input
A vulnerability in the PE file format parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition, or possibly other expanded impacts, resulting from memory corruption on an affected device. This vulnerability is due to improper b
- 7.6 High severity
FatFs: Buffer Copy without Checking Size of Input
FatFs R0.16 and earlier contains a downstream-caller vulnerability pattern associated with FatFs long filename handling. With LFN enabled, fno.fname can be up to 255 characters; many callers copy it into short fixed buffers without bounds checks, causing overf
- 8.8 High severity
EW-7478APC: Improper Restriction of Operations within the Bounds of a Memory Buffer
A vulnerability has been found in Edimax EW-7478APC 1.04. Impacted is the function formUSBFolder of the file /goform/formUSBFolder of the component POST Request Handler. Such manipulation of the argument ShareName/SelectName leads to buffer overflow. The attac