Keylime's registrar vulnerable to Denial-of-service attack via a single open connection

Description

Impact

Keylime registrar is prone to a simple denial of service attack in which an adversary opens a connection to the TLS port (by default, port 8891) blocking further, legitimate connections. As long as the connection is open, the registrar is blocked and cannot serve any further clients (agents and tenants), which prevents normal operation. The problem does not affect the verifier.

Patches

Users should upgrade to release 7.4.0

Basic information

Type
reviewed
Severity
high
Advisory on GitHub
Open advisory ↗
Repository advisory
Open repository advisory ↗
Source code
Browse source ↗
Published (advisory)
2023-08-01 20:16:29 UTC
Updated
2023-09-04 05:04:37 UTC
GitHub reviewed
2023-08-01 20:16:29 UTC

EPSS Score

Score Percentile
0.24% 47.84%

CVSS Scores

Base score Version Severity Vector
7.5 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.

Identifiers

CWEs

CWE id Name
CWE-834 Excessive Iteration

Affected packages (1)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
pip keylime < 7.4.0 7.4.0

References

cvelogic Threat Intelligence