CVE-2024-5552: Kubeflow ReDoS Denial of Service Vulnerability

CVE-2024-5552 Overview

CVE-2024-5552 is a Regular Expression Denial of Service (ReDoS) vulnerability affecting kubeflow/kubeflow. The flaw resides in the email validation logic of the centraldashboard-angular backend component. An unauthenticated remote attacker can submit specially crafted input that triggers catastrophic backtracking in the email validation regular expression. The resulting CPU exhaustion disrupts service availability for users of the central dashboard. The weakness is tracked as CWE-1333: Inefficient Regular Expression Complexity.

Critical Impact
Unauthenticated attackers can exhaust backend CPU resources by submitting crafted email strings, causing denial of service against the Kubeflow central dashboard.

Affected Products

Kubeflow kubeflow (latest version at time of disclosure)
centraldashboard-angular backend component
Deployments exposing the central dashboard to untrusted networks

Discovery Timeline

2024-06-06 - CVE-2024-5552 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2024-5552

Vulnerability Analysis

The vulnerability exists in the email validation routine used by the centraldashboard-angular backend in Kubeflow. The validator relies on a regular expression whose pattern contains ambiguous quantifiers that produce exponential backtracking on certain inputs. When the engine evaluates a crafted string that nearly matches the expected email format, it explores an exponentially growing number of states before failing. This consumes CPU cycles on the Node.js event loop and blocks concurrent requests.

Because the validator is reachable on a network-accessible endpoint without authentication, any remote client can submit malicious payloads. Repeated submissions amplify the impact and can stall the dashboard backend entirely. Exploitation requires no privileges and no user interaction.

Root Cause

The root cause is inefficient regular expression complexity [CWE-1333]. The pattern used to validate email addresses contains overlapping character classes with unbounded repetition, allowing a single input to produce many possible match paths. Regex engines using backtracking, including the default JavaScript engine, evaluate these paths sequentially, leading to algorithmic complexity attacks.

Attack Vector

An attacker sends HTTP requests carrying crafted email-shaped strings to any endpoint of the central dashboard backend that invokes the vulnerable validator. The payload typically consists of long sequences of characters that satisfy the ambiguous portions of the pattern followed by a character that forces match failure. The backend thread processing the request enters a long-running regex evaluation and cannot service other clients during that period. Multiple parallel requests scale the impact across worker processes. See the Huntr Bug Bounty Report for additional technical context.

Detection Methods for CVE-2024-5552

Indicators of Compromise

Sustained high CPU utilization on centraldashboard-angular backend pods without corresponding legitimate traffic volume.
HTTP request bodies or query parameters containing unusually long email-shaped strings with repeated character classes.
Increased request latency or timeouts on dashboard endpoints that accept email input.

Detection Strategies

Inspect application logs for slow request durations correlated with email validation handlers.
Deploy a Web Application Firewall (WAF) rule that flags or blocks email parameters exceeding a reasonable length threshold (for example 254 characters per RFC 5321).
Monitor Node.js event loop lag metrics on dashboard pods as a leading indicator of regex stalls.

Monitoring Recommendations

Alert on Kubernetes pod CPU saturation combined with HTTP 5xx or timeout spikes on the central dashboard service.
Track request rate and payload size distributions for endpoints that accept user-supplied email values.
Forward dashboard access logs to a centralized analytics platform to correlate latency anomalies with source IPs.

How to Mitigate CVE-2024-5552

Immediate Actions Required

Restrict network access to the Kubeflow central dashboard using Kubernetes NetworkPolicy or an upstream reverse proxy until a patched release is deployed.
Enforce request size and field length limits on any endpoint that accepts email input to bound regex execution time.
Place rate limiting in front of the dashboard backend to reduce the amplification potential of repeated malicious requests.

Patch Information

At the time of publication, no fixed version was listed in the NVD record. Operators should track the upstream kubeflow/kubeflow repository and the Huntr Bug Bounty Report for remediation guidance and upgrade to the first release that replaces the vulnerable regex with a linear-time validator.

Workarounds

Front the dashboard with an ingress or proxy that validates email parameters using a non-backtracking regex engine or a simple length and structural check.
Restrict dashboard access to authenticated internal users via single sign-on (SSO) and remove any unauthenticated exposure to the internet.
Configure timeouts on backend HTTP handlers to terminate requests that exceed expected processing duration.

bash

# Example NetworkPolicy restricting access to the central dashboard
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: restrict-centraldashboard
  namespace: kubeflow
spec:
  podSelector:
    matchLabels:
      app: centraldashboard
  policyTypes:
  - Ingress
  ingress:
  - from:
    - namespaceSelector:
        matchLabels:
          name: trusted-clients
    ports:
    - protocol: TCP
      port: 8082