Full Report
BlackHat Vegas is almost on us again, and this will be the 6th year running that we present there.. This year Marco and i will be taking a new look at some old attacks.. The bulk of the talk will focus (like its name suggests) on timing attacks, but we will be looking in general at timing, race conditions and other attacks that have not yet been packaged into tools and so are not yet prone to the type of over-fishing we have found with fuzzable bugs..
Analysis Summary
# Tool/Technique: Timing Attacks and Race Conditions
## Overview
The focus of the presentation is a re-examination of older, fundamental security flaws, specifically **timing attacks** and **race conditions**. These techniques exploit anomalies in the timing of operations or concurrent execution to infer sensitive information or manipulate system states, often before formalized tools are widely developed for them. The presenters note that these attacks are currently less prone to mass-detection ("over-fishing") because they are not yet packaged into standardized tools like fuzzable bugs.
## Technical Details
- Type: Technique
- Platform: General (Applicable to various platforms/applications where timing and concurrent operations are present)
- Capabilities: Inferring secret data based on variable execution times, or achieving unauthorized state changes via simultaneous operations.
- First Seen: Ancient/Classic security concepts, in this context presented as "old attacks."
## MITRE ATT&CK Mapping
This summary maps the *concepts* described, which are typically exploited via custom code or through existing system vulnerabilities.
- **TA0001 - Initial Access** (If timing is used during authentication/enumeration)
- **T1071 - Application Layer Protocol** (If communication timing is analyzed)
- **TA0006 - Credential Access**
- **T1003 - OS Credential Dumping** (Timing attacks can potentially assist in inferring secrets like passwords or keys if cryptographic operations leak timing data related to complexity/correctness)
- **TA0011 - Command and Control** (Less direct, but timing can be related to network monitoring)
- **TA0004 - Privilege Escalation**
- **T1548 - Abuse Elevation Control Mechanism** (Race conditions are classic for achieving unauthorized privilege escalation)
## Functionality
### Core Capabilities
- **Timing Attacks:** Exploiting minute differences in the time taken for an operation to complete to deduce information about secret inputs (e.g., lengths of passwords, contents of secret keys during cryptographic comparison).
- **Race Conditions:** Exploiting uncertain, interdependent execution sequences between two or more threads or processes to achieve an outcome not intended by the design (e.g., accessing a file before permissions checks are finalized).
### Advanced Features
- Exploiting flaws that have **not yet been packaged into tools**, suggesting the techniques are tailored or conceptual, making them difficult for automated, signature-based defenses (like fuzzers) to catch.
## Indicators of Compromise
Since these are intellectual techniques rather than specific malware artifacts, IOCs are highly contextual to the implementation.
- File Hashes: N/A (Technique)
- File Names: N/A (Technique)
- Registry Keys: N/A (Technique)
- Network Indicators: N/A (Technique, though network latency measurement may be part of an external timing attack)
- Behavioral Indicators:
- Unusually accurate measurement of execution time differences between logically similar operations.
- Unplanned success of operations requiring strict temporal ordering (indicating a successful race condition exploitation).
## Associated Threat Actors
This describes techniques that can be used by virtually any advanced threat actor, researcher, or penetration tester.
- **General Adversaries:** Researchers, pen-testers, and sophisticated threat actors capable of low-level system analysis.
## Detection Methods
Detection focuses on anomalies in system behavior and timing, rather than static artifacts.
- **Signature-based detection:** Ineffective unless a specific, known timing attack tool is executed.
- **Behavioral detection:** Monitoring for application logic anomalies, or excessive auditing/logging of time-sensitive system calls. Strong application auditing can reveal timing variations.
- **YARA rules:** N/A (Technique)
## Mitigation Strategies
Mitigation requires robust defensive programming practices addressing both timing leakage and concurrency control.
- **Prevention Measures:**
- **Constant-Time Programming:** Ensuring cryptographic and authentication routines execute in a time independent of the secret data being processed.
- **Secure Concurrency Primitives:** Utilizing atomic operations, comprehensive locking mechanisms, or transactional memory to prevent data races.
- **Input Validation:** Performing input validation early in the process to minimize data-dependent execution paths.
- **Hardening Recommendations:** Thorough code review focusing specifically on branching logic related to variable inputs and thread synchronization points.
## Related Tools/Techniques
- Side-Channel Attacks (Broader category encompassing timing attacks)
- Fault Injection Attacks (Often related to race/timing exploitation against hardware barriers)
- Software Fuzzing (The article explicitly notes that these techniques differ from fuzzable bugs that are often targeted by modern tools.)