Security vulnerabilities and automated fixes for rate limiting issues
6 posts found
A Node.js authentication service exposed unauthenticated OTP endpoints without adequate rate limiting, allowing attackers to exhaust email service quotas through repeated requests. The fix implements per-session resend caps and cooldown enforcement to prevent email-based denial of service attacks while preserving legitimate user workflows.
A critical vulnerability in express-rate-limit versions prior to 8.2.2 allowed attackers to bypass per-client rate limiting on dual-stack servers by exploiting incorrect IPv6 subnet masking. When IPv4 clients connected through IPv4-mapped IPv6 addresses (like ::ffff:192.0.2.1), the library failed to properly identify unique clients, enabling unlimited requests that could lead to denial of service. The fix upgrades express-rate-limit to 8.2.2 and its dependency ip-address to 10.1.0, implementing
Three public API endpoints in a Next.js application — `/api/send-review`, `/api/contact`, and `/api/auth` — were deployed without any server-side rate limiting, allowing attackers to flood them with unlimited requests. The `/api/send-review` and `/api/contact` endpoints were especially dangerous because every request triggered an outbound email via Gmail SMTP, making them prime targets for email bombing and quota exhaustion. The fix introduces a lightweight in-memory rate limiter capping each IP
A missing batch size limit in `BatchModeRunner.jsx` allowed users to trigger unlimited LLM API calls by pasting thousands of items into the batch input field. This could exhaust shared API quotas in organizational settings where a single API key is distributed across multiple users. The fix introduces a hard cap of 25 items (`MAX_BATCH_SIZE = 25`) enforced directly in the `canRun()` validation function.
A critical rate limiting vulnerability in an Express.js application allowed attackers to bypass API throttling through IP rotation and header manipulation. This fix demonstrates how improperly configured rate limiters can be circumvented through proxy networks, VPNs, and forged X-Forwarded-For headers, potentially enabling brute force attacks, credential stuffing, and resource exhaustion.
A medium-severity vulnerability (CVE-2026-24842) in node-tar allowed attackers to create arbitrary files outside intended directories by exploiting a flaw in hardlink security checks. Combined with missing rate limiting controls, this vulnerability exposed applications to both path traversal attacks and denial-of-service through unlimited automated requests. Here's what happened and how to protect your applications.