CWE-208 (通过时间差异性导致的信息暴露) — Vulnerability Class 173

173 vulnerabilities classified as CWE-208 (通过时间差异性导致的信息暴露). AI Chinese analysis included.

CWE-208 represents an information leakage weakness where an application’s response time varies based on internal state, inadvertently revealing sensitive data to external observers. Attackers typically exploit this by measuring the duration of operations, such as login attempts or database queries, to infer the existence of valid usernames or correct password characters. By analyzing these subtle timing differences, adversaries can bypass authentication mechanisms or extract confidential information without direct access. To mitigate this risk, developers must ensure that all security-critical operations take a constant amount of time, regardless of the outcome. This involves implementing uniform error handling, using constant-time comparison algorithms for secrets, and avoiding early returns that expose processing stages. By standardizing execution duration, applications prevent attackers from leveraging timing discrepancies to gain unauthorized insights into system states or credentials.

MITRE CWE 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.

Common Consequences (1)

Confidentiality, Access Control Read Application Data, Bypass Protection Mechanism

Examples (2)

Consider an example hardware module that checks a user-provided password to grant access to a user. The user-provided password is compared against a golden value in a byte-by-byte manner.

always_comb @ (posedge clk) begin assign check_pass[3:0] = 4'b0; for (i = 0; i < 4; i++) begin if (entered_pass[(i*8 - 1) : i] eq golden_pass([i*8 - 1) : i]) assign check_pass[i] = 1; continue; else assign check_pass[i] = 0; break; end assign grant_access = (check_pass == 4'b1111) ? 1'b1: 1'b0; end

Bad · Verilog

always_comb @ (posedge clk) begin assign check_pass[3:0] = 4'b0; for (i = 0; i < 4; i++) begin if (entered_pass[(i*8 - 1) : i] eq golden_pass([i*8 -1) : i]) assign check_pass[i] = 1; continue; else assign check_pass[i] = 0; continue; end assign grant_access = (check_pass == 4'b1111) ? 1'b1: 1'b0; end

Good · Verilog

In this example, the attacker observes how long an authentication takes when the user types in the correct password.

def validate_password(actual_pw, typed_pw): if len(actual_pw) <> len(typed_pw): return 0 for i in len(actual_pw): if actual_pw[i] <> typed_pw[i]: return 0 return 1

Bad · Python

CVE ID	Title	CVSS	Severity	Published
CVE-2013-10006	Ziftr primecoin bitcoinrpc.cpp HTTPAuthorized timing discrepancy — primecoin	2.6	Low	2023-01-01
CVE-2022-4823	InSTEDD Nuntium geopoll_controller.rb timing discrepancy — Nuntium	3.1	Low	2022-12-28
CVE-2021-4294	OpenShift OSIN CheckClientSecret timing discrepancy — OSIN	2.6	Low	2022-12-28
CVE-2022-39308	GoCD API authentication of user access tokens subject to timing attack during comparison — gocd	6.5	Medium	2022-10-14
CVE-2022-31142	Potential Timing Attack Vector in @fastify/bearer-auth — fastify-bearer-auth	7.5	High	2022-07-14
CVE-2022-20752	Cisco Unified Communications Products Timing Attack Vulnerability — Cisco Unified Communications Manager	5.3	Medium	2022-07-06
CVE-2022-29185	Observable Timing Discrepancy in totp-rs — totp-rs	4.2	Medium	2022-05-20
CVE-2021-42016	Siemens RUGGEDCOM 安全漏洞 — RUGGEDCOM i800	7.5	High	2022-03-08
CVE-2021-43298	Embedthis Software GoAhead 安全漏洞 — goahead	9.1	-	2022-01-25
CVE-2021-26318	Side-channels Related to the x86 PREFETCH Instruction — All supported processors	4.7	-	2021-10-13
CVE-2021-26314	AMD Speculative execution with Floating-Point Value Injection — All supported processors	5.5	-	2021-06-09
CVE-2021-26313	AMD Speculative Code Store Bypass — All supported processors	5.5	-	2021-06-09
CVE-2021-31403	Timing side channel vulnerability in UIDL request handler in Vaadin 7 and 8 — Vaadin	4.0	Medium	2021-04-23
CVE-2021-31404	Timing side channel vulnerability in UIDL request handler in Vaadin 10, 11-14, and 15-18 — Vaadin	4.0	Medium	2021-04-23
CVE-2021-31406	Timing side channel vulnerability in endpoint request handler in Vaadin 15-19 — Vaadin	4.0	Medium	2021-04-23
CVE-2020-1926	Timing attack in Cookie signature verification — Apache Hive	5.9	-	2021-03-16
CVE-2020-15237	Timing attack in Shrine — shrine	5.9	Medium	2020-10-05
CVE-2020-4071	Timing attack on django-basic-auth-ip-whitelist — django-basic-auth-ip-whitelist	2.2	Low	2020-06-24
CVE-2020-11037	Potential Observable Timing Discrepancy in Wagtail — Wagtail	6.1	Medium	2020-04-30
CVE-2019-16782	Possible Information Leak / Session Hijack Vulnerability in Rack — rack	6.3	Medium	2019-12-18
CVE-2019-13420	floragunn Search Guard 信息泄露漏洞 — Search Guard	5.9	-	2019-08-13
CVE-2019-9494	The implementations of SAE in hostapd and wpa_supplicant are vulnerable to side-channel attacks — hostapd with SAE support	5.9	-	2019-04-17
CVE-2016-10535	csrf-lite 安全漏洞 — csrf-lite node module	5.9	-	2018-05-31

Vulnerabilities classified as CWE-208 (通过时间差异性导致的信息暴露) represent 173 CVEs. The CWE taxonomy describes the weakness; review individual CVEs for product-specific impact.