Weakness · High
CWE-273: Improper Check for Dropped Privileges
What it is
The product attempts to drop privileges but does not check or incorrectly checks to see if the drop succeeded.
- Severity (our rating)
- High
- Likelihood of exploit
- Medium
- Introduced during
- Implementation
- Exploited in the wild
- 1 known exploited CVE
In more detail
If the drop fails, the product will continue to run with the raised privileges, which might provide additional access to unprivileged users.
What an attacker can do
- Gain Privileges or Assume Identity (Access Control, Non-Repudiation)
- Hide Activities (Access Control, Non-Repudiation)
How to prevent it
Architecture and Design
- Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.
Implementation
- Check the results of all functions that return a value and verify that the value is expected.
- In Windows, make sure that the process token has the SeImpersonatePrivilege(Microsoft Server 2003). Code that relies on impersonation for security must ensure that the impersonation succeeded, i.e., that a proper privilege demotion happened.
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.)
Exploited in the wild: 1 CVE
Vulnerabilities caused by CWE-273 that attackers have used, from CISA's Known Exploited Vulnerabilities catalog, newest first.
H2 Security
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Start freeSource: MITRE Common Weakness Enumeration, CWE version 4.19.1. CWE is a trademark of The MITRE Corporation.