CAPEC-59: Session Credential Falsification through Prediction
CAPEC版本: 3.9
更新日期: 2023-01-24
攻击模式描述
This attack targets predictable session ID in order to gain privileges. The attacker can predict the session ID used during a transaction to perform spoofing and session hijacking.
执行流程
步骤 1 Explore
[Find Session IDs] The attacker interacts with the target host and finds that session IDs are used to authenticate users.
- An attacker makes many anonymous connections and records the session IDs assigned.
- An attacker makes authorized connections and records the session tokens or credentials issued.
步骤 2 Explore
[Characterize IDs] The attacker studies the characteristics of the session ID (size, format, etc.). As a results the attacker finds that legitimate session IDs are predictable.
- Cryptanalysis. The attacker uses cryptanalysis to determine if the session IDs contain any cryptographic protections.
- Pattern tests. The attacker looks for patterns (odd/even, repetition, multiples, or other arithmetic relationships) between IDs
- Comparison against time. The attacker plots or compares the issued IDs to the time they were issued to check for correlation.
步骤 3 Experiment
[Match issued IDs] The attacker brute forces different values of session ID and manages to predict a valid session ID.
- The attacker models the session ID algorithm enough to produce a compatible session IDs, or just one match.
步骤 4 Exploit
[Use matched Session ID] The attacker uses the falsified session ID to access the target system.
- The attacker loads the session ID into their web browser and browses to restricted data or functionality.
- The attacker loads the session ID into their network communications and impersonates a legitimate user to gain access to data or functionality.
前提条件
- The target host uses session IDs to keep track of the users.
- Session IDs are used to control access to resources.
- The session IDs used by the target host are predictable. For example, the session IDs are generated using predictable information (e.g., time).
所需技能
后果影响
影响范围: Confidentiality Access Control Authorization
技术影响: Gain Privileges
缓解措施
Use a strong source of randomness to generate a session ID.
Use adequate length session IDs
Do not use information available to the user in order to generate session ID (e.g., time).
Ideas for creating random numbers are offered by Eastlake [RFC1750]
Encrypt the session ID if you expose it to the user. For instance session ID can be stored in a cookie in encrypted format.
示例实例
Jetty before 4.2.27, 5.1 before 5.1.12, 6.0 before 6.0.2, and 6.1 before 6.1.0pre3 generates predictable session identifiers using java.util.random, which makes it easier for remote attackers to guess a session identifier through brute force attacks, bypass authentication requirements, and possibly conduct cross-site request forgery attacks. See also: CVE-2006-6969
mod_usertrack in Apache 1.3.11 through 1.3.20 generates session ID's using predictable information including host IP address, system time and server process ID, which allows local users to obtain session ID's and bypass authentication when these session ID's are used for authentication. See also: CVE-2001-1534
分类映射
| 分类名称 | 条目ID | 条目名称 |
|---|---|---|
| WASC | 18 | Credential/Session Prediction |
| OWASP Attacks | - | Session Prediction |