CWE-822: Untrusted Pointer Dereference

CWE-822: Untrusted Pointer Dereference is a Common Weakness Enumeration (CWE) entry maintained by MITRE. The product obtains a value from an untrusted source, converts this value to a pointer, and dereferences the resulting pointer. An attacker can supply a pointer for memory locations that the product is not expecting. If the pointer is dereferenced for a write operation, the attack might allow modification of critical state variables, cause a crash, or execute code. If the dereferencing operation is for a read, then the attack might allow reading of sensitive data, cause a crash, or set a variable to an unexpected value (since the value will be read from an unexpected memory location). There are several variants of this weakness, including but not necessarily limited to: The untrusted value is directly invoked as a function call. In OS kernels or drivers where there is a boundary between "userland" and privileged memory spaces, an untrusted pointer might enter through an API or system call (see CWE-781 for one such example). Inadvertently accepting the value from an untrusted control sphere when it did not have to be accepted as input at all. This might occur when the code was originally developed to be run by a single user in a non-networked environment, and the code is then ported to or otherwise exposed to a networked environment.

If exploited, CWE-822 (Untrusted Pointer Dereference) it can compromise Confidentiality, Availability and Integrity, leading to outcomes such as Read Memory, DoS: Crash, Exit, or Restart, Execute Unauthorized Code or Commands and Modify Memory.

CWE-822 commonly affects C, C++ and Memory-Unsafe. Note that weaknesses are often language-agnostic patterns, so secure coding practices apply broadly.

MITRE documents real CVEs mapped to CWE-822, including CVE-2007-5655, CVE-2010-2299, CVE-2009-1719, CVE-2009-1250 and CVE-2009-0311. You can look up the full details of each CVE, including CVSS scores and remediation guidance, on our CVE Lookup tool.

A CWE (Common Weakness Enumeration) like CWE-822 describes a category of software weakness — the underlying flaw type. A CVE (Common Vulnerabilities and Exposures) identifies a specific, real-world vulnerability in a particular product. In short, a CWE is the kind of mistake, and a CVE is an instance of that mistake being found in software.