CWE-494: Download of Code Without Integrity Check
Official CWE-494 CWE context with Glexia analysis, remediation guidance, related CVEs, and ATT&CK context.
Glexia's Take
CWE-494: Download of Code Without Integrity Check
Download of Code Without Integrity Check represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Executive Impact
- Integrity,Availability,Confidentiality,Other: Execute Unauthorized Code or Commands,Alter Execution Logic,Other: Executing untrusted code could compromise the control flow of the program. The untrusted code could execute attacker-controlled commands, read or modify sensitive resources, or prevent the software from functioning correctly for legitimate users.
Developer Pattern
CWE-494 is the kind of defect developers can usually prevent with explicit validation, safer framework defaults, and tests that exercise hostile input or unsafe state transitions.
Confidence
high confidence from CWE-494, 4.20.
Official CWE Definition
CWE-494: Download of Code Without Integrity Check
The product downloads source code or an executable from a remote location and executes the code without sufficiently verifying the origin and integrity of the code.
An attacker can execute malicious code by compromising the host server, performing DNS spoofing, or modifying the code in transit.
Developer And Remediation Guidance
How teams prevent and detect this weakness
Causes
- This example loads an external class from a local subdirectory. This code does not ensure that the class loaded is the intended one, for example by verifying the class's checksum. An attacker may be able to modify the class file to execute malicious code.
- This code includes an external script to get database credentials, then authenticates a user against the database, allowing access to the application. This code does not verify that the external domain accessed is the intended one. An attacker may somehow cause the external domain name to resolve to an attack server, which would provide the information for a false database. The attacker may then steal the usernames and encrypted passwords from real user login attempts, or simply allow themself to access the application without a real user account.,This example is also vulnerable to an Adversary-in-the-Middle AITM (CWE-300) attack.
Remediation
- Implementation: Perform proper forward and reverse DNS lookups to detect DNS spoofing.
- Architecture and Design,Operation: [object Object]
- Architecture and Design: [object Object]
- Architecture and Design,Operation: Run your code using the lowest privileges that are required to accomplish the necessary tasks [REF-76]. If possible, create isolated accounts with limited privileges that are only used for a single task. That way, a successful attack will not immediately give the attacker access to the rest of the software or its environment. For example, database applications rarely need to run as the database administrator, especially in day-to-day operations.
Detection
- Manual Analysis: [object Object]
- Black Box: [object Object]
- Automated Static Analysis: Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)
Mappings
Related CVEs, CWEs, and ATT&CK context
Related CWEs
ATT&CK Relevance
ATT&CK relevance is shown only when reviewed or responsibly inferred.