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Weakness · High

CWE-785: Use of Path Manipulation Function without Maximum-sized Buffer

What it is

The product invokes a function for normalizing paths or file names, but it provides an output buffer that is smaller than the maximum possible size, such as PATH_MAX.

1 exploited in the wildMITRE CWE 4.19.1

Severity (our rating)
High
Likelihood of exploit
Not rated by MITRE
Introduced during
Implementation
Exploited in the wild
1 known exploited CVE

In more detail

Passing an inadequately-sized output buffer to a path manipulation function can result in a buffer overflow. Such functions include realpath(), readlink(), PathAppend(), and others.

What an attacker can do

  • Modify Memory (Integrity, Confidentiality, Availability)
  • Execute Unauthorized Code or Commands (Integrity, Confidentiality, Availability)
  • DoS: Crash, Exit, or Restart (Integrity, Confidentiality, Availability)

How to prevent it

Implementation

  • Always specify output buffers large enough to handle the maximum-size possible result from path manipulation functions.

How to find it

  • 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.)

CWE-785 on MITRE's CWE site

Exploited in the wild: 1 CVE

Vulnerabilities caused by CWE-785 that attackers have used, from CISA's Known Exploited Vulnerabilities catalog, newest first.

All known exploited vulnerabilities

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Source: MITRE Common Weakness Enumeration, CWE version 4.19.1. CWE is a trademark of The MITRE Corporation.