Weakness (CWE)
CWE-476: NULL Pointer Dereference
The product dereferences a pointer that it expects to be valid but is NULL.
How to prevent it (5 mitigations)
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Implementation
For any pointers that could have been modified or provided from a function that can return NULL, check the pointer for NULL before use. When working with a multithreaded or otherwise asynchronous environment, ensure that proper locking APIs are used to lock before the check, and unlock when it has finished [REF-1484].
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Requirements
Select a programming language that is not susceptible to these issues.
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Implementation
Check the results of all functions that return a value and verify that the value is non-null before acting upon it.
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Architecture and Design
Identify all variables and data stores that receive information from external sources, and apply input validation to make sure that they are only initialized to expected values.
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Implementation
Explicitly initialize all variables and other data stores, either during declaration or just before the first usage.
Source: MITRE CWE-476
2,662 results · Feed
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Medium 5.4
NULL Pointer Dereference in H5HL_unprotect via Corrupted File
HDF5 through 2.2.0 contains a NULL pointer dereference vulnerability in H5HL_unprotect() in src/H5HL.c. H5HL_protect() pins a single metadata cache entry for a local heap, either the heap prefix or the separate data block, and H5HL_unprotect() unpins it on th…
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Medium 6.9
A NULL pointer dereference in the Linux GPU driver could potentially lead to a kernel crash and result in denial of ser…
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Medium 6.5
FreeRDP before 3.32.2 X11 Client Crash via Zero-Width RDPGFX ResetGraphics
FreeRDP before 3.32.2 contains a NULL pointer dereference vulnerability that allows malicious RDP servers to crash xfreerdp clients by sending a zero-width RDPGFX ResetGraphics PDU. The failed resize in gdi_resize_ex leaves the primary display null without en…
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Medium 4.3
FreeRDP before 3.32.2 Denial of Service via RD Gateway extended-auth packet
FreeRDP before 3.32.2 contains a denial of service vulnerability where rdg_process_packet dispatches a PKT_TYPE_EXTENDED_AUTH_MSG without verifying negotiated mode or auth context. A malicious or compromised RD Gateway can send the extended-auth packet before…
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High 8.2
NULL pointer dereference in the BSD raw IPv6 send path when the destination table is full
In Eclipse ThreadX NetX Duo versions 6.0 through 6.5.2.202603a, built with BSD raw socket and IPv6 support, the IPv6 raw send path uses the destination-table entry it adds without checking that the add succeeded. When the destination table is full and an off-…
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High 8.7
NULL pointer dereference in ICMPv6 Packet Too Big processing when the destination table is full
In Eclipse ThreadX NetX Duo versions 6.4.5.202504 through 6.5.2.202603a, built with IPv6 path MTU discovery, the ICMPv6 Packet Too Big handler uses the destination-table entry it adds without checking that the add succeeded. A sender on the network can fill t…
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Medium 5.5
The Sleuth Kit through 4.15.0 NULL Pointer Dereference via decmpfs LZVN Decompression
The Sleuth Kit through 4.15.0 contains a NULL pointer dereference vulnerability in decmpfs_decompress_lzvn_attr() that allows attackers to crash the tool by supplying a crafted HFS+ image. Attackers can set a huge uncompressed_size in an LZVN inline com.apple…
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Medium 6.5
Picotls has NULL pointer dereference during handshake, when running as a client
Picotls is a TLS protocol library that allows users select different crypto backends based on their use case. In affected revisions through 44bc503, when picotls is used as a `client-side TLS stack`, a peer can send a `HelloRetryRequest` followed by a `spoofe…
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High 7.5
ESPAsyncWebServer multipart parser has null-pointer write
ESPAsyncWebServer is an asynchronous HTTP and WebSocket server library for ESP32, ESP8266, RP2040 and RP2350. Prior to version 3.11.2, the multipart parser in `src/WebRequest.cpp` frees `_itemBuffer` and sets it to NULL when `BOUNDARY_OR_DATA` matches the clo…
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None 0.0
asn1c: ASAN crash with decode of open types
mouse07410/asn1c is an ASN.1 compiler. Prior to 1.2.5, `OPEN TYPE` decoding can dereference an unallocated member pointer and crash the consuming program. `OPEN_TYPE_aper_get` in `OPEN_TYPE_aper.c`, `OPEN_TYPE_ber_get` in `OPEN_TYPE_ber.c`, `OPEN_TYPE_oer_get…
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Medium 5.3
Nezha 2.0.0 before 2.4.0 Startup NULL Pointer Dereference via Orphaned Service History
Nezha 2.0.0 before 2.4.0 contains a NULL pointer dereference vulnerability in ServiceSentinel.loadTodayStats that allows authenticated users to crash the dashboard by deleting a service. Attackers can delete their own service via POST /api/v1/batch-delete/ser…
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Medium 6.5
Gst-plugins-base: gst-plugins-base: null-pointer dereference in mdvdsub subtitle parser via missing closing-brace check
A flaw was found in GStreamer's gst-plugins-base MicroDVD subtitle parser. When processing a specially crafted subtitle file, the parser may dereference a NULL pointer, causing the application to crash when a user opens or plays media with a malformed MicroDV…
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Medium 6.5
Gst-plugins-bad: gst-plugins-bad: null pointer dereference in h.264 mvc sps cleanup during parse failure
A flaw was found in the H.264 video parser in gst-plugins-bad. When processing a specially crafted H.264 video file or network stream with malformed Multiview (MVC) Sequence Parameter Set data, the parser can dereference a NULL pointer during the cleanup of p…
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High 7.5
sniproxy through 0.7.0 NULL Pointer Dereference via resolv_cancel()
sniproxy through 0.7.0 contains a NULL pointer dereference vulnerability in resolv_cancel() that allows remote unauthenticated attackers to crash the daemon by sending overlong hostnames. Attackers can send a 254 or 255 character TLS SNI name or HTTP Host hea…
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Medium 4.3
NULL pointer dereference vulnerability in QCborValue to JSON conversion impacts Qt
A NULL pointer dereference vulnerability in the Qt QCborValue to JSON conversion of the Qt Core module.
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High 7.5
Forge: Denial of service in TLS record processing via a record interleaved with a fragmented handshake message
Forge (also called node-forge) is a native implementation of Transport Layer Security in JavaScript. Prior to 1.4.1, the affected implementation used forge.tls.createConnection(), fragmented handshake message, interleaved record to process the relevant input …
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Medium 5.9
Forge: TLS client crash when the server sends no certificate
Forge (also called node-forge) is a native implementation of Transport Layer Security in JavaScript. Prior to 1.4.1, the affected implementation used forge.tls.createConnection(), c.session.serverCertificate, RSA key exchange to process the relevant input or …
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High 8.7
NULL pointer dereference on implicit read of user specific record index
P-Net before 1.0.3 dereferences a NULL AR pointer in pf_fspm_cm_read_ind() when handling an implicit read request without a valid target AR UUID for a user specific record index, if the application has registered a read callback. A remote unauthenticated atta…
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High 8.7
NULL pointer dereference on implicit read of AR specific record index
P-Net before 1.0.3 dereferences a NULL AR pointer when handling an implicit read request without a valid target AR UUID for a record index that requires an AR (AR specific indices 0xE000-0xEFFF, and the expected identification data of a slot or subslot). A re…
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Medium 6.5
389-ds-base: 389-ds-base: null pointer dereference via modifydn using an attribute's schema alias name causes denial of service
A NULL pointer dereference flaw was found in 389-ds-base. This flaw occurs when a ModifyDN (rename) operation uses an attribute's schema alias name (such as "commonName") instead of its canonical name (such as "cn") as the new relative distinguished name. An …
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Medium 5.9
libexpat through 2.9.0 NULL Pointer Dereference via External Entity Subparser
libexpat through 2.9.0 contains a NULL pointer dereference vulnerability in externalEntityInitProcessor2() in lib/xmlparse.c that mishandles the XML_TOK_NONE token from empty input. Attackers who control stream chunking can force an empty non-final first pars…
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High 7.5
Asterisk: NULL Pointer Dereference in HTTP AMI Digest Authentication
Asterisk is an open source private branch exchange and telephony toolkit. Prior to Asterisk 20.20.1, 21.12.3, 22.10.1, 23.4.1 and Certified Asterisk 20.7-cert11, 22.8-cert3, a NULL pointer dereference in the `Asterisk Manager Interface (AMI)` may allow an una…
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Medium 6.5
Tanium addressed a denial of service vulnerability in Enforce.
Tanium addressed a denial of service vulnerability in Enforce.
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High 8.7
Fireware OS NULL Pointer Dereference in Management Interface Allows Unauthenticated Denial of Service
A NULL pointer dereference vulnerability in WatchGuard Fireware OS’s management interface allows a remote, unauthenticated attacker with network access to the management interface to crash the management service by sending a specially crafted login request. R…
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Medium 6.5
libcss through 0.9.2 NULL Pointer Dereference via Media-Query Parser
libcss through 0.9.2 contains a NULL pointer dereference vulnerability in mq_parse_media_query() that allows remote attackers to crash consumers by supplying media lists ending in a comma. Attackers can serve a stylesheet whose @media or @import media list ha…
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High 7.5
A null pointer dereference was addressed with improved input validation. This issue is fixed in iOS 27 and iPadOS 27, m…
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Medium 6.5
A null pointer dereference was addressed with improved validation. This issue is fixed in iOS 26.7.2 and iPadOS 26.7.2,…
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Medium 4.6
A null pointer dereference was addressed with improved validation. This issue is fixed in iOS 26.7.2 and iPadOS 26.7.2,…
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Medium 6.2
ONNX: Null Pointer Dereference in ScanInferenceFunction Due to Missing Required Attribute
Open Neural Network Exchange (ONNX) is an open standard for machine learning interoperability. From 1.4.0 until 1.22.0, ScanInferenceFunction, ScanInferenceFunction_opset8, and ScanInferenceFunction_opset9 do not safely validate the required num_scan_inputs a…
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Medium 6.5
Bluetooth Classic HFP AG wipes an object still linked in the SDP request list on connect failure, causing a NULL dereference
In the Bluetooth Classic Hands-Free Profile Audio Gateway role, hfp_ag_create() in subsys/bluetooth/host/classic/hfp_ag.c starts an SDP discovery toward the peer, which links the embedded ag->sdp_param._node into the SDP client's pending request list in subsy…
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Medium 5.5
Gssproxy: gssproxy: null pointer dereference in gssx_init_sec_context crashes daemon
A NULL pointer dereference vulnerability was found in gssproxy. When a GSSX_INIT_SEC_CONTEXT request is received with the target_name field absent, the daemon dereferences the resulting NULL pointer and crashes. The request requires no authentication, allowin…
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Low 2.1
Null pointer dereference vulnerability in QNetworkAccessManager impacts Qt
A malicious or compromised HTTP/2 server withholding SETTINGS ACK can send RST_STREAM on a completed stream, planting a null pointer, and then send a PUSH_PROMISE for that stream, causing a null pointer dereference in the QNetworkAccessManager class of the Qt…
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Medium 6.5
Null Pointer Dereference in Mailbox Error Handling
SOEM version 2.0.0 and earlier contains a vulnerability where a malicious device can crash the master system. When the software receives an error response, it clears an internal pointer but continues processing. If another message arrives before timeout, the …
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Low 3.7
ImageMagick before 6.9.13-58 and 7.x before 7.1.2-33 Null Pointer Dereference in DJVU Decoder
ImageMagick before 6.9.13-58 and 7.x before 7.1.2-33 contains a null pointer dereference in the DJVU decoder because the result of a memory allocation is not checked before use. Attackers can supply a DJVU image that, when processed under conditions where the…
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High 7.5
Kiloview E3 NDI Encoder NULL Pointer Dereference
The ONVIF service on the E3 can be rendered unresponsive by sending malformed or incomplete requests to certain operations. The affected service stops accepting new connections while the rest of the device continues operating normally, and will recover automa…
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Medium 5.9
Apache Traffic Server: Nullptr dereference in net_write_io on a POST half-close with chunked response
Apache Traffic Server can crash with a null pointer dereference when a client POST request is torn down via half-close while a chunked origin response is being reparsed from a reentrant write-ready callback, a timing-dependent race introduced by the CVE-2021-…
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High 7.1
NULL pointer dereference in the MCTP I2C+GPIO target binding triggerable by a peer I2C controller
The MCTP-over-I2C+GPIO target binding in subsys/pmci/mctp/mctp_i2c_gpio_target.c emulates a small pseudo-register file, where the bus controller first writes a register number and then writes or reads payload bytes. The selected register (b->reg_addr) and the…
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High 7.5
Cisco Expressway Series Software Hardening Release: October 2026 - NULL Pointer Vulnerabilities
As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco Expressway Series software engineering team has conducted a comprehensive internal security review. This review resulted in software hardening releases that address mul…
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Medium 5.8
Multiple Cisco Products Snort 3 Generic Routing Encapsulation Denial of Service Vulnerabilities
Multiple Cisco products are affected by a vulnerability in the generic routing encapsulation (GRE) tunnel decapsulation feature of the Snort 3 Detection Engine that could allow an unauthenticated, remote attacker to cause an unexpected restart of the Snort 3 …
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High 7.5
Named may terminate unexpectedly when a redirect zone is used with strict QNAME minimization
A BIND resolver that is configured with both a "redirect" zone and "qname-minimization strict" may abort with an assertion failure while processing the redirect. This issue affects BIND 9 versions 9.16.0 through 9.18.50, 9.20.0 through 9.20.29, 9.21.0 through…