Description
Two separate operations in a product require different amounts of time to complete, in a way that is observable to an actor and reveals security-relevant information about the state of the product, such as whether a particular operation was successful or not.
In security-relevant contexts, even small variations in timing can be exploited by attackers to indirectly infer certain details about the product’s internal operations. For example, in some cryptographic algorithms, attackers can use timing differences to infer certain properties about a private key, making the key easier to guess. Timing discrepancies effectively form a timing side channel.
Modes of Introduction:
– Architecture and Design
Related Weaknesses
Consequences
Confidentiality, Access Control: Read Application Data, Bypass Protection Mechanism
Potential Mitigations
CVE References
- CVE-2003-0078
- SSL implementation does not perform a MAC computation if an incorrect block cipher padding is used, which causes an information leak (timing discrepancy) that may make it easier to launch cryptographic attacks that rely on distinguishing between padding and MAC verification errors, possibly leading to extraction of the original plaintext, aka the “Vaudenay timing attack.”
- CVE-2000-1117
- Virtual machine allows malicious web site operators to determine the existence of files on the client by measuring delays in the execution of the getSystemResource method.
- CVE-2003-0637
- Product uses a shorter timeout for a non-existent user than a valid user, which makes it easier for remote attackers to guess usernames and conduct brute force password guessing.
- CVE-2003-0190
- Product immediately sends an error message when a user does not exist, which allows remote attackers to determine valid usernames via a timing attack.
- CVE-2004-1602
- FTP server responds in a different amount of time when a given username exists, which allows remote attackers to identify valid usernames by timing the server response.
- CVE-2005-0918
- Browser allows remote attackers to determine the existence of arbitrary files by setting the src property to the target filename and using Javascript to determine if the web page immediately stops loading, which indicates whether the file exists or not.