Leverage Executable Code in Nonexecutable Files
Attack Pattern ID: 35 (Standard Attack Pattern Completeness: Complete)Typical Severity: Very HighStatus: Draft
+ Description


An attack of this type exploits a system's trust in configuration and resource files, when the executable loads the resource (such as an image file or configuration file) the attacker has modified the file to either execute malicious code directly or manipulate the target process (e.g. application server) to execute based on the malicious configuration parameters. Since systems are increasingly interrelated mashing up resources from local and remote sources the possibility of this attack occurring is high.

The attack can be directed at a client system, such as causing buffer overrun through loading seemingly benign image files, as in Microsoft Security Bulletin MS04-028 where specially crafted JPEG files could cause a buffer overrun once loaded into the browser. Another example targets clients reading pdf files. In this case the attacker simply appends javascript to the end of a legitimate url for a pdf (http://www.gnucitizen.org/blog/danger-danger-danger/)


The client assumes that they are reading a pdf, but the attacker has modified the resource and loaded executable javascript into the client's browser process.

The attack can also target server processes. The attacker edits the resource or configuration file, for example a web.xml file used to configure security permissions for a J2EE app server, adding role name "public" grants all users with the public role the ability to use the administration functionality.

< security-constraint>
<description>Security processing rules for admin screens</description>

The server trusts its configuration file to be correct, but when they are manipulated, the attacker gains full control.

+ Attack Prerequisites

The attacker must have the ability to modify nonexecutable files consumed by the target software.

+ Typical Likelihood of Exploit

Likelihood: High

+ Methods of Attack
  • Injection
  • API Abuse
  • Modification of Resources
+ Examples-Instances


Virtually any system that relies on configuration files for runtime behavior is open to this attack vector. The configuration files are frequently stored in predictable locations, so an attacker that can fingerpint a server process such as a web server or database server can quickly identify the likely locale where the configuration is stored. And this is of course not limited to server processes. Unix shells rely on profile files to store environment variables, search paths for programs and so on. If the aliases are changed, then a standard Unix "cp" command can be rerouted to "rm" or other standard command so the user's intention is subverted.

+ Attacker Skills or Knowledge Required

Skill or Knowledge Level: Low

To identify and execute against an overprivileged system interface

+ Resources Required

Ability to communicate synchronously or asynchronously with server that publishes an overprivileged directory, program, or itnerface. Optionally, ability to capture output directly through synchronous communication or other method such as FTP.

+ Solutions and Mitigations

Design: Enforce principle of least privilege

Design: Run server interfaces with a non-root account and/or utilize chroot jails or other configuration techniques to constrain privileges even if attacker gains some limited access to commands.

Implementation: Perform testing such as pentesting and vulnerability scanning to identify directories, programs, and interfaces that grant direct access to executables.

Implementation: Implement host integrity monitoring to detect any unwanted altering of configuration files.

Implementation: Ensure that files that are not required to execute, such as configuration files, are not over-privileged, i.e. not allowed to execute.

+ Attack Motivation-Consequences
  • Run Arbitrary Code
  • Data Modification
  • Privilege Escalation
+ Injection Vector

Nonexecutable files

+ Payload

Executable code

+ Activation Zone

Client machine and client network

+ Payload Activation Impact

Enables attacker to execute server side code with any commands that the program owner has privileges to.

+ Related Weaknesses
CWE-IDWeakness NameWeakness Relationship Type
94Failure to Control Generation of Code ('Code Injection')Targeted
96Improper Neutralization of Directives in Statically Saved Code ('Static Code Injection')Targeted
95Improper Sanitization of Directives in Dynamically Evaluated Code ('Eval Injection')Targeted
97Failure to Sanitize Server-Side Includes (SSI) Within a Web PageTargeted
272Least Privilege ViolationSecondary
59Improper Link Resolution Before File Access ('Link Following')Secondary
282Improper Ownership ManagementSecondary
275Permission IssuesSecondary
264Permissions, Privileges, and Access ControlsSecondary
270Privilege Context Switching ErrorSecondary
714OWASP Top Ten 2007 Category A3 - Malicious File ExecutionTargeted
+ Related Vulnerabilities
Vulnerability IDRelationship Description
Microsoft Security Bulletin MS04-028

Buffer Overrun in JPEG Processing (GDI+) Could Allow Code Execution

+ Related Attack Patterns
NatureTypeIDNameDescriptionView(s) this relationship pertains toView\(s\)
PeerOfAttack PatternAttack Pattern23File System Function Injection, Content Based 
Mechanism of Attack1000
PeerOfAttack PatternAttack Pattern75Manipulating Writeable Configuration Files 
Mechanism of Attack1000
ChildOfAttack PatternAttack Pattern165File Manipulation 
Mechanism of Attack (primary)1000
PeerOfAttack PatternAttack Pattern44Overflow Binary Resource File 
Mechanism of Attack1000
+ Purposes
  • Exploitation
+ CIA Impact
Confidentiality Impact: MediumIntegrity Impact: HighAvailability Impact: Low
+ Technical Context
Architectural Paradigms
+ References
G. Hoglund and G. McGraw. "Exploiting Software: How to Break Code". Addison-Wesley. February 2004.
+ Content History
G. Hoglund and G. McGraw. Exploiting Software: How to Break Code. Addison-Wesley, February 2004.Cigital, Inc2007-01-01
Gunnar PetersonCigital, Inc2007-02-28Fleshed out content to CAPEC schema from the original descriptions in "Exploiting Software"
Sean BarnumCigital, Inc2007-03-09Review and revise
Richard StruseVOXEM, Inc2007-03-26Review and feedback leading to changes in Related Attack Patterns
Sean BarnumCigital, Inc2007-04-13Modified pattern content according to review and feedback