Weakness (CWE)
CWE-120: Buffer Copy without Checking Size of Input
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.
How to prevent it (8 mitigations)
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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.
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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 [REF-57], and the Strsafe.h library from Microsoft [REF-56]. These libraries provide safer versions of overflow-prone string-handling functions.
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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 [REF-1334] discusses canary-based detection in detail.
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Implementation
Consider adhering to the following rules when allocating and managing an application's memory:
- Double check that your buffer is as large as you specify.
- When using functions that accept a number of bytes to copy, such as strncpy(), be aware that if the destination buffer size is equal to the source buffer size, it may not NULL-terminate the string.
- Check buffer boundaries if accessing the buffer in a loop and make sure there is no danger of writing past the allocated space.
- If necessary, truncate all input strings to a reasonable length before passing them to the copy and concatenation functions.
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Implementation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue."
Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
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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.
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Operation, Build and Compilation
Run or compile the software using features or extensions that randomly arrange the positions of a program's executable and libraries in memory. Because this makes the addresses unpredictable, it can prevent an attacker from reliably jumping to exploitable code.
Examples include Address Space Layout Randomization (ASLR) [REF-58] [REF-60] and Position-Independent Executables (PIE) [REF-64]. Imported modules may be similarly realigned if their default memory addresses conflict with other modules, in a process known as "rebasing" (for Windows) and "prelinking" (for Linux) [REF-1332] using randomly generated addresses. ASLR for libraries cannot be used in conjunction with prelink since it would require relocating the libraries at run-time, defeating the whole purpose of prelinking.
For more information on these techniques see D3-SAOR (Segment Address Offset Randomization) from D3FEND [REF-1335].
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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 [REF-60] [REF-61]. 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 [REF-1336].
Source: MITRE CWE-120
3,302 results · Feed
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Low 2.0
VMDP: Potential buffer overflow in the RtlQueryRegistryValues function
A Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') vulnerability in SUSE Virtual Machine Driver Pack allows an attacker with the ability to modify the registry to affect the integrity of the driver. We're not aware of a feasible way to e…
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Critical 9.8
Buffer Overflow vulnerability in OpenHTJ2K v.0.18.4 and before allows an attacker to execute arbitrary code via the ope…
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High 8.8
Tenda CH22 CertListInfo formCertListInfo buffer overflow
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 publ…
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High 8.8
TRENDnet TEW-821DAP ssi tools_nslookup sub_41EC14 buffer overflow
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. Th…
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High 8.8
TRENDnet TEW-821DAP ssi tools_nslookup sub_41EC14 buffer overflow
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 t…
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High 8.2
U-Boot < 2026.07-rc2 Buffer Overflow in nfs_readlink_reply() via NFS READLINK
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 r…
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High 7.8
Foxit PDF Editor/Reader Signature Buffer Overflow Vulnerability
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.
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High 7.7
WatchGuard Firebox admd Out of Bounds Write Vulnerability
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 i…
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High 8.3
GeoVision GeoWebPlayer Websocket Server connectInfo handler stack-based buffer overflow vulnerability
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 var…
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High 8.3
GeoVision GeoWebPlayer Websocket Server connectInfo handler stack-based buffer overflow vulnerability
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 var…
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High 8.3
GeoVision GeoWebPlayer Websocket Server connectInfo handler stack-based buffer overflow vulnerability
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 var…
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High 8.3
GeoVision GeoWebPlayer Websocket Server connectInfo handler stack-based buffer overflow vulnerability
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 var…
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High 8.3
GeoVision GeoWebPlayer Websocket Server connectInfo handler stack-based buffer overflow vulnerability
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 var…
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High 8.3
GeoVision GeoWebPlayer Websocket Server connectInfo handler stack-based buffer overflow vulnerability
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 var…
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High 7.5
Buffer Overflow vulnerability in UTT nv518G nv518GV3v3.2.7-210919-161313 allows a remote attacker to cause a denial of …
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High 7.5
Buffer Overflow vulnerability in UTT nv518G nv518GV3v3.2.7-210919-161313 allows a remote attacker to cause a denial of …
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High 7.5
Buffer Overflow vulnerability in UTT nv518G nv518GV3v3.2.7-210919-161313 allows a remote attacker to cause a denial of …
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High 7.5
ClamAV ALZ Archive Processing Denial of Service Vulnerability
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…
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High 7.5
ClamAV DMG File Processing Denial of Service Vulnerability
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…
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High 7.5
ClamAV 7Zip File Format Processing Out-of-Bounds Memory Corruption Vulnerability
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 …
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High 7.5CVE-2026-20217 Public exploit
ClamAV PESpin File Format Processing Out-of-Bounds Memory Corruption Vulnerability
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 impro…
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High 7.5
ClamAV PE File Format Processing Out-of-Bounds Memory Corruption Vulnerability
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 …
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High 7.5
ClamAV FSG File Format Processing Out-of-Bounds Memory Corruption Vulnerability
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…
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High 7.6
FatFs Buffer Overflow via Unbounded LFN Filename Copy
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 over…
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High 7.5
Buffer Overflow vulnerability in UTT nv518G nv518GV3v3.2.7-210919-161313 allows a remote attacker to cause a denial of …
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High 7.5
Buffer Overflow vulnerability in UTT nv518G nv518GV3v3.2.7-210919-161313 allows a remote attacker to cause a denial of …
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High 7.5
Buffer Overflow vulnerability in UTT nv518G nv518GV3v3.2.7-210919-161313 allows a remote attacker to cause a denial of …
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High 7.5
Buffer Overflow vulnerability in UTT nv518G nv518GV3v3.2.7-210919-161313 allows a remote attacker to cause a denial of …
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High 8.8
Edimax EW-7478APC POST Request formUSBFolder buffer overflow
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 atta…
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High 8.8
Edimax EW-7478APC POST Request formUSBAccount buffer overflow
A flaw has been found in Edimax EW-7478APC 1.04. This issue affects the function formUSBAccount of the file /goform/formUSBAccount of the component POST Request Handler. This manipulation of the argument UserName/Password causes buffer overflow. The attack is…
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High 8.8
Edimax EW-7478APC POST Request formQoS buffer overflow
A security vulnerability has been detected in Edimax EW-7478APC 1.04. This affects the function formQoS of the file /goform/formQoS of the component POST Request Handler. The manipulation of the argument selSSID leads to buffer overflow. Remote exploitation o…
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High 8.8
Edimax EW-7478APC POST Request formiNICSiteSurvey buffer overflow
A flaw has been found in Edimax EW-7478APC 1.04. This affects the function formiNICSiteSurvey of the file /goform/formiNICSiteSurvey of the component POST Request Handler. This manipulation of the argument selSSID causes buffer overflow. It is possible to ini…
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Medium 5.9
Envoy Heap Buffer Overflow in TcpStatsdSink
Envoy is an open source edge and service proxy designed for cloud-native applications. From 1.34.0 until 1.35.13, 1.36.9, 1.37.5, and 1.38.3, a vulnerability exists in Envoy's TCP StatsD sink (TcpStatsdSink), where the thread-local flusher buffer can be overf…
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High 7.5
GV-LPC2011/LPC2211 - unauthorized buffer overflow vulnerability (IEEE8021x_upload.cgi)
An unauthenticated buffer overflow vulnerability exists in IEEE8021x_upload.cgi in GeoVision GV-LPC2011 and GV-LPC2211 V1.12 and earlier. The vulnerability is caused by insufficient bounds checking when parsing filename values in multipart upload data. A remo…
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Low 1.0
PKCS#7 decode ignores caller output buffer size, writing past buffer bounds
The PKCS#7 decode path ignores the caller-supplied output buffer size (outputSz), allowing decoded content to be written past the bounds of the provided buffer. This affects wolfSSL 5.9.0 and earlier and was fixed in the 5.9.1 release.
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High 7.1
accel/ivpu: Add buffer overflow check in MS get_info_ioctl
In the Linux kernel, the following vulnerability has been resolved: accel/ivpu: Add buffer overflow check in MS get_info_ioctl Add validation that the info size returned from the metric stream info query is not exceeded when checked against the allocated buff…
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High 7.2
Out of bounds stack write with crafted APL RR
NSD version 4.14.0 introduced a bug where a specially crafted APL RR, with an adflength larger than permitted for the address family will overwrite the stack when the zone is written to disk, with a maximum of 111 attacker controlled bytes.
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High 8.4
OpenColorIO vulnerable to stack buffer overflow via unbounded `sscanf %s` in Spi3D (.spi3d) LUT parser
OpenColorIO is a color management framework for visual effects and animation. Prior to version 2.5.2, `FileFormatSpi3D.cpp:163` uses `sscanf` with `%s` into 64-byte stack buffers when parsing LUT data lines. Input comes from `lineBuffer[4096]`, so a crafted .…
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Critical 9.3
Electron: Buffer performs incorrect byte length calculations resulting in heap buffer under/overflow
Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. From 42.3.1 until 42.3.3, Buffer performs incorrect byte length calculations resulting in heap buffer under/overflow. Most apps will crash and some may per…
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High 8.8
Edimax BR-6478AC V2 POST Request formWlSiteSurvey buffer overflow
A vulnerability has been found in Edimax BR-6478AC V2 1.23. The impacted element is the function formWlSiteSurvey of the file /goform/formWlSiteSurvey of the component POST Request Handler. The manipulation of the argument selSSID leads to buffer overflow. It…