Weakness (CWE)
CWE-754: Improper Check for Unusual or Exceptional Conditions
The product does not check or incorrectly checks for unusual or exceptional conditions that are not expected to occur frequently during day to day operation of the product.
How to prevent it (7 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.
Choose languages with features such as exception handling that force the programmer to anticipate unusual conditions that may generate exceptions. Custom exceptions may need to be developed to handle unusual business-logic conditions. Be careful not to pass sensitive exceptions back to the user (CWE-209, CWE-248).
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Implementation
Check the results of all functions that return a value and verify that the value is expected.
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Implementation
If using exception handling, catch and throw specific exceptions instead of overly-general exceptions (CWE-396, CWE-397). Catch and handle exceptions as locally as possible so that exceptions do not propagate too far up the call stack (CWE-705). Avoid unchecked or uncaught exceptions where feasible (CWE-248).
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Implementation
Ensure that error messages only contain minimal details that are useful to the intended audience and no one else. The messages need to strike the balance between being too cryptic (which can confuse users) or being too detailed (which may reveal more than intended). The messages should not reveal the methods that were used to determine the error. Attackers can use detailed information to refine or optimize their original attack, thereby increasing their chances of success.
If errors must be captured in some detail, record them in log messages, but consider what could occur if the log messages can be viewed by attackers. Highly sensitive information such as passwords should never be saved to log files.
Avoid inconsistent messaging that might accidentally tip off an attacker about internal state, such as whether a user account exists or not.
Exposing additional information to a potential attacker in the context of an exceptional condition can help the attacker determine what attack vectors are most likely to succeed beyond DoS.
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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, Implementation
If the program must fail, ensure that it fails gracefully (fails closed). There may be a temptation to simply let the program fail poorly in cases such as low memory conditions, but an attacker may be able to assert control before the software has fully exited. Alternately, an uncontrolled failure could cause cascading problems with other downstream components; for example, the program could send a signal to a downstream process so the process immediately knows that a problem has occurred and has a better chance of recovery.
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Architecture and Design
Use system limits, which should help to prevent resource exhaustion. However, the product should still handle low resource conditions since they may still occur.
Source: MITRE CWE-754
267 results · Clear filters · Feed
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Medium 6.5
Posting a malicious markdown image crashes the Mattermost Desktop App
Mattermost Desktop App versions <=6.2 5.5.13 6.0.2.0 fail to properly null check when checking for headers in the Mattermost Desktop App which allows any user to crash another channel members Desktop App via posting a malicious link with an embedded image tha…
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Medium 4.7
Junos OS: MX Series: For subscribers configured on static interfaces, input filters are not in effect
An Improper Check for Unusual or Exceptional Conditions vulnerability in the packet forwarding engine (PFE) of Juniper Networks Junos OS on MX Series allows adjacent subscribers to bypass configured firewall filters. On MX Series devices with MPC10/11, LC4800…
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Medium 5.9
Junos OS: MX Series with SPC3, SRX Series: Specific packet in response to a TCP connection establishment by the affected device can crash the PFE
An Improper Check for Unusual or Exceptional Conditions vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on MX with SPC3 and SRX Series allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS). When …
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Medium 6.5
Junos OS: QFX10000 Series: IPv6 multicast traffic received on non-IRB interfaces causes a multicast flood
An Improper Check for Unusual or Exceptional Conditions vulnerability in the packet forwarding engine (pfe) of Juniper Networks Junos OS on QFX10000 Series allows an unauthenticated, adjacent attacker to cause a Denial-of-Service (DoS). On all QFX10000 platfo…
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Medium 6.5
Junos OS and Junos OS Evolved: When a specifically malformed BGP route update is received RPD crashes
An Improper Check for Unusual or Exceptional Conditions vulnerability in the routing protocol daemon (RPD) of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent, unauthenticated attacker sending a specific BGP update over an established BGP ses…
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Medium 5.9
Junos OS Evolved: PTX Series: Receipt of repeated ECMP routing updates results in PFE crash
An Improper Check for Unusual or Exceptional Conditions vulnerability in the advanced forwarding toolkit (evo-aftmand) of Juniper Networks Junos OS Evolved on PTX Series allows an unauthenticated network-based attacker generating continuous routing updates, r…
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Medium 4.6
PAN-OS: Denial of Service Vulnerabilities in Network Traffic Processing
Multiple denial of service vulnerabilities in Palo Alto Networks PAN-OS® software allow an unauthenticated attacker with network access to cause a denial of service (DoS) condition by sending specially crafted network traffic to or through a dataplane interfa…
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Medium 6.5
CoreWCF: Kafka consume pump halts permanently on a Kafka tombstone (null-value record), causing persistent endpoint denial of service.
CoreWCF is a port of the service side of Windows Communication Foundation (WCF) to .NET Core. Prior to 1.8.1 and 1.9.1, a CoreWCF service listening on a Kafka topic stops processing new records from that topic when KafkaTransportPump receives a null-value tom…
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Medium 6.3
Phoenix JavaScript presence client crashes on presence keys colliding with Object.prototype members in Presence.syncState/syncDiff
Improper Check for Unusual or Exceptional Conditions vulnerability in phoenixframework phoenix (Presence JavaScript client) allows an attacker with ordinary channel access to cause a persistent client-side denial of service against every viewer of a presence …
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Medium 5.9
ImageMagick: Heap Buffer Overflow in ImageMagick MVG decoder
ImageMagick is free and open-source software used for editing and manipulating digital images. Prior to versions 6.9.13-51 and 7.1.2-26, a heap buffer overflow occurs in the MVG decoder that could result in an out of bounds write when processing a crafted ima…
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Medium 5.3
protobufjs: Schema-derived names can shadow runtime-significant properties
protobufjs compiles protobuf definitions into JavaScript (JS) functions. Prior to 8.6.0 and 7.6.3, protobufjs accepted certain schema-derived names that could collide with properties used by protobufjs runtime helpers. The known affected names are fields name…
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Medium 4.6
PAN-OS: Denial of Service (DoS) in Tunnel Traffic Processing
A memory corruption vulnerability in the processing of tunnel traffic in Palo Alto Networks PAN-OS® software allows an authenticated user to initiate system reboots using a maliciously crafted packet. Repeated attempts to initiate a reboot causes the firewall…
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Medium 4.6
Indian Scout Bobber 2025 WCM CAN bus-off attack silently bypasses anti-theft shutdown
Expected behavior violation in the in-vehicle network of the Indian Motorcycle Scout Bobber + Tech 2025 model year allows an adjacent-network attacker to bypass the motorcycle's anti-theft shutdown by forcing the Wireless Control Module (WCM) into the CAN bus…
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Medium 4.6
Indian Scout Bobber 2025 WCM voltage-based shutdown
Improper handling of physical conditions in the bike-shutdown control of the Indian Motorcycle Scout Bobber + Tech 2025 model year allows a physical attacker with access to the Wireless Control Module (WCM) wiring harness to bypass the anti-theft shutdown. Th…
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Medium 6.5
free5GC: PCF npcf-policyauthorization POST /app-sessions panics on suppFeat=1 with missing AfRoutReq via nil pointer dereference
free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's PCF POST /npcf-policyauthorization/v1/app-sessions handler panics on a single authenticated request whose ascReqData.suppFeat == "1" (enabling traffic-routing feature n…
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Medium 6.5
free5GC: UDR nudr-dr DELETE amf-subscriptions panics on missing UE state via nil interface type assertion (single authenticated request)
free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's UDR nudr-dr DELETE /subscription-data/{ueId}/{servingPlmnId}/ee-subscriptions/{subsId}/amf-subscriptions handler panics on a single authenticated request against a fres…
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Medium 6.5
Server panic via outgoing webhook responses
Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to filter nil elements from outgoing webhook attachment payloads before processing, which allows an authenticated user to cause a denial of service (server proc…
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Medium 4.3
nimiq-blockchain: network-libp2p untrusted peer can crash address book via empty peer contact addresses
nimiq-blockchain provides persistent block storage for Nimiq's Rust implementation. In versions 1.3.0 and prior, network-libp2p discovery accepts signed PeerContact updates from untrusted peers and stores them in a peer contact book, eventually leading to add…
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Medium 5.5
Improper Check for Unusual or Exceptional Conditions vulnerability in Samsung Open Source Escargot allows Input Data Ma…
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Medium 4.3
SVG content served through Mattermost image proxy despite Content-Type restrictions causes client-side denial of service
Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 Fail to validate the response body of proxied images, which allows a remote attacker to enact client-side DoS via an SVG file served from an attacker-controlled origin under a non-SVG…
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Medium 5.1
Trust Protection Foundation: Multiple Authorization Bypass Vulnerabilities
Incorrect Authorization vulnerabilities in Trust Protection Foundation allow attackers to bypass access controls and perform unauthorized actions on restricted resources.
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Medium 5.8
Prisma Browser: Access and Data Rule Bypass
A race condition vulnerability in Palo Alto Networks Prisma® Browser enables a locally authenticated non-admin user to bypass certain access and data control policies.
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Medium 6.6
PAN-OS: Denial of Service Vulnerabilities in Network Traffic Parsing
Multiple denial of service vulnerabilities in Palo Alto Networks PAN-OS® software allow an unauthenticated attacker with network access to cause a denial of service (DoS) condition by sending specially crafted network traffic. Panorama and Cloud NGFW are not …
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Medium 4.3
ELECOM wireless LAN access point devices do not check if language parameter has an appropriate value. If a user views a…
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Medium 6.9
Improper conditions check in some firmware for some Intel(R) NPU Drivers within Ring 1: Device Drivers may allow a deni…
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Medium 5.2
Admidio: Missing Minimum Administrator Check in Role Membership Removal
Admidio is an open-source user management solution. Prior to version 5.0.9, Role::stopMembership() does not verify whether removing a user from the administrator role leaves zero administrators. The deprecated Membership::stopMembership() contains this safety…
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Medium 4.6
OpenClaw < 2026.3.31 - Fail-Open Security Scan Bypass in Plugin Installation
OpenClaw before 2026.3.31 contains a fail-open vulnerability in the plugin installation flow where security scan failures do not block installation. Attackers can exploit scan failures to install untrusted plugins when operators proceed despite visible scan w…
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Medium 5.3
nimiq-blockchain: Peer-triggerable panic during history sync
nimiq-blockchain provides persistent block storage for Nimiq's Rust implementation. Prior to version 1.3.0, `HistoryStore::put_historic_txns` uses an `assert!` to enforce invariants about `HistoricTransaction.block_number` (must be within the macro block bein…
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Medium 5.5
uutils coreutils kill System-wide Process Termination and Denial of Service via Argument Misinterpretation
An argument parsing error in the kill utility of uutils coreutils incorrectly interprets kill -1 as a request to send the default signal (SIGTERM) to PID -1. Sending a signal to PID -1 causes the kernel to terminate all processes visible to the caller, potent…
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Medium 4.4
uutils coreutils printenv Security Inspection Bypass via UTF-8 Enforcement
The printenv utility in uutils coreutils fails to display environment variables containing invalid UTF-8 byte sequences. While POSIX permits arbitrary bytes in environment strings, the uutils implementation silently skips these entries rather than printing th…
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Medium 6.9
free5GC UDR: Fail-open handling in PolicyDataSubsToNotifyPost allows unintended subscription creation
free5GC UDR is the user data repository (UDR) for free5GC, an an open-source project for 5th generation (5G) mobile core networks. In versions up to and including 1.4.2, a fail-open request handling flaw in the UDR service causes the `/nudr-dr/v2/policy-data/…
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Medium 6.9
free5gc UDR fail-open request handling in PolicyDataSubsToNotifySubsIdPut may allow unintended subscription updates after input errors
free5GC is an open-source implementation of the 5G core network. In versions 4.2.1 and below of the UDR service, the PUT handler for updating Policy Data notification subscriptions at /nudr-dr/v2/policy-data/subs-to-notify/{subsId} does not return after reque…
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Medium 4.1
Dell PowerScale OneFS, versions prior to 9.12.0.0, contains an improper check for unusual or exceptional conditions vul…
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Medium 5.5
Junos OS: SRX1500, SRX4100, SRX4200, SRX4600: When a specific show command is executed chassisd crashes
An Improper Check for Unusual or Exceptional Conditions vulnerability in the chassis control daemon (chassisd) of Juniper Networks Junos OS on SRX1500, SRX4100, SRX4200 and SRX4600 allows a local attacker with low privileges to cause a complete Denial of Serv…
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Medium 6.5
Junos OS: EX Series, QFX Series: In a VXLAN scenario when specific control protocol packets are received, memory leaks and eventually no traffic is passed
An Improper Check for Unusual or Exceptional Conditions vulnerability in the packet forwarding engine (pfe) of Juniper Networks Junos OS on specific EX and QFX Series devices allow an unauthenticated, adjacent attacker to cause a complete Denial of Service (D…
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Medium 6.5
Junos OS: MX Series: Firewall filters on lo0.<non-0> in the default routing instance are not in effect
An Improper Check for Unusual or Exceptional Conditions vulnerability in the packet forwarding engine (pfe) of Juniper Networks Junos OS on MX Series allows an unauthenticated, network-based attacker to bypass the configured firewall filter and access the con…
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Medium 5.5
Junos OS: SRX1600, SRX2300, SRX4300: When a specific show command is executed chassisd crashes
An Improper Check for Unusual or Exceptional Conditions vulnerability in the chassis control daemon (chassisd) of Juniper Networks Junos OS on SRX1600, SRX2300 and SRX4300 allows a local attacker with low privileges to cause a complete Denial of Service (DoS)…
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Medium 4.3
Cosign's verify-blob-attestation reports false positive when payload parsing fails
Cosign provides code signing and transparency for containers and binaries. Prior to 3.0.6 and 2.6.3, cosign verify-blob-attestation may erroneously report a "Verified OK" result for attestations with malformed payloads or mismatched predicate types. For old-f…
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Medium 4.3
DoS via URL Previews Rendering Malicious SVGs
Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to prevent rendering of external SVGs on link embeds which allows unauthenticated users to crash the Mattermost webapp and desktop app via creating an issue or …
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Medium 4.0
Cortex XDR Agent: Local Administrator can disable the agent on macOS
A problem with a protection mechanism in the Palo Alto Networks Cortex XDR agent on macOS allows a local administrator to disable the agent. This issue could be leveraged by malware to perform malicious activity without detection.