Obscured Security-relevant Information by Alternate Name

The software records security-relevant information according to an alternate name of the affected entity, instead of the canonical name.


Demonstrations

The following examples help to illustrate the nature of this weakness and describe methods or techniques which can be used to mitigate the risk.

Note that the examples here are by no means exhaustive and any given weakness may have many subtle varieties, each of which may require different detection methods or runtime controls.

Example One

This code prints the contents of a file if a user has permission.

function readFile($filename){

  $user = getCurrentUser();
  $realFile = $filename;

  //resolve file if its a symbolic link
  if(is_link($filename)){
    $realFile = readlink($filename);
  }

  if(fileowner($realFile) == $user){
    echo file_get_contents($realFile);
    return;
  }
  else{
    echo 'Access denied';
    writeLog($user . ' attempted to access the file '. $filename . ' on '. date('r'));
  }

}

While the code logs a bad access attempt, it logs the user supplied name for the file, not the canonicalized file name. An attacker can obscure their target by giving the script the name of a link to the file they are attempting to access. Also note this code contains a race condition between the is_link() and readlink() functions (CWE-363).

See Also

Audit / Logging Errors

Weaknesses in this category are related to audit-based components of a software system. Frequently these deal with logging user activities in order to identify undesir...

Audit

Weaknesses in this category are related to the design and architecture of audit-based components of the system. Frequently these deal with logging user activities in o...

SFP Secondary Cluster: Information Loss

This category identifies Software Fault Patterns (SFPs) within the Information Loss cluster.

Comprehensive CWE Dictionary

This view (slice) covers all the elements in CWE.

Weaknesses without Software Fault Patterns

CWE identifiers in this view are weaknesses that do not have associated Software Fault Patterns (SFPs), as covered by the CWE-888 view. As such, they represent gaps in...

Weaknesses Introduced During Implementation

This view (slice) lists weaknesses that can be introduced during implementation.


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