The product's comparison logic is performed over a series of steps rather than across the entire string in one operation. If there is a comparison logic failure on one of these steps, the operation may be vulnerable to a timing attack that can result in the interception of the process for nefarious purposes.
Comparison logic is used to compare a variety of objects including passwords, Message Authentication Codes (MACs), and responses to verification challenges. When comparison logic is implemented at a finer granularity (e.g., byte-by-byte comparison) and breaks in the case of a comparison failure, an attacker can exploit this implementation to identify when exactly the failure occurred. With multiple attempts, the attacker may be able to guesses the correct password/response to challenge and elevate their privileges.
| Nature | Mapping | Type | ID | Name |
|---|---|---|---|---|
| ChildOf | Allowed | B | 208 | Observable Timing Discrepancy |
| ChildOf | Discouraged | P | 697 | Incorrect Comparison |
| ParentOf | Allowed | B | 1261 | Improper Handling of Single Event Upsets |
| Nature | Mapping | Type | ID | Name |
|---|---|---|---|---|
| MemberOf | Prohibited | C | 1199 | General Circuit and Logic Design Concerns |
| MemberOf | Prohibited | C | 1417 | Comprehensive Categorization: Sensitive Information Exposure |
| Nature | Mapping | Type | ID | Name |
|---|---|---|---|---|
| MemberOf | Prohibited | BS | BOSS-294 | Not Language-Specific Weaknesses |
| MemberOf | Prohibited | BS | BOSS-298 | Not OS-Specific(os class) Weaknesses |
| MemberOf | Prohibited | BS | BOSS-301 | Not Architecture-Specific (architecture class) Weaknesses |
| MemberOf | Prohibited | BS | BOSS-307 | Not Technology-Specific (technology class) Weaknesses |
| MemberOf | Prohibited | BS | BOSS-316 | Bypass Protection Mechanism (impact) |
| Nature | Mapping | Type | ID | Name |
|---|---|---|---|---|
| MemberOf | Prohibited | C | 1199 | General Circuit and Logic Design Concerns |
| Scope | Likelihood | Impact | Note |
|---|---|---|---|
| ConfidentialityAuthorization | N/A | Bypass Protection Mechanism | N/A |
The hardware designer should ensure that comparison logic is implemented so as to compare in one operation instead in smaller chunks.
N/A
N/A
| Reference | Description |
|---|---|
| CVE-2019-10482 | Smartphone OS uses comparison functions that are not in constant time, allowing side channels |
| CVE-2019-10071 | Java-oriented framework compares HMAC signatures using String.equals() instead of a constant-time algorithm, causing timing discrepancies |
| CVE-2014-0984 | Password-checking function in router terminates validation of a password entry when it encounters the first incorrect character, which allows remote attackers to obtain passwords via a brute-force attack that relies on timing differences in responses to incorrect password guesses, aka a timing side-channel attack. |
| Ordinality | Description |
|---|
This CWE entry is at the Base level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.
Carefully read both the name and description to ensure that this mapping is an appropriate fit. Do not try to 'force' a mapping to a lower-level Base/Variant simply to comply with this preferred level of abstraction.
CWE 4.16 removed a demonstrative example for a hardware module because it was inaccurate and unable to be adapted. The CWE team is developing an alternative.
N/A
| Taxonomy Name | Entry ID | Fit | Entry Name |
|---|