Cyber Resilience

CVE-2024-34535

Joinmastodon Mastodon ≤ 4.1.16

Published
03 October 2024
Modified
06 May 2025
CVSS Score v3.1 5.9
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:N
EPSS Score 0.0038 30th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2024-34535 is a medium-severity HTTP Request/Response Smuggling (CWE-444) vulnerability in Joinmastodon Mastodon. Its CVSS base score is 5.9 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Password Guessing (T1110.001); ranked at the 30th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

In Mastodon 4.1.6, API endpoint rate limiting can be bypassed by setting a crafted HTTP request header.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1110.001 Password Guessing Credential Access
Adversaries with no prior knowledge of legitimate credentials within the system or environment may guess passwords to attempt access to accounts.
T1098 Account Manipulation Persistence
Adversaries may manipulate accounts to maintain and/or elevate access to victim systems.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Why these techniques?

Missing rate limiting on password change endpoint enables password guessing (T1110.001) and subsequent account manipulation via password change (T1098) when using a stolen session cookie; vulnerability in public-facing Mastodon API facilitates exploitation of public-facing application (T1190).

CVEs Like This One

CVE-2026-23964Same product: Joinmastodon Mastodon
CVE-2026-27477Same product: Joinmastodon Mastodon
CVE-2026-41259Same product: Joinmastodon Mastodon
CVE-2026-25540Same product: Joinmastodon Mastodon
CVE-2026-22245Same product: Joinmastodon Mastodon
CVE-2026-33869Same product: Joinmastodon Mastodon
CVE-2026-23962Same product: Joinmastodon Mastodon
CVE-2026-27468Same product: Joinmastodon Mastodon
CVE-2026-22246Same product: Joinmastodon Mastodon
CVE-2023-42450Same product: Joinmastodon Mastodon

Affected Assets

joinmastodon
mastodon
≤ 4.1.16 · 4.2.0 — 4.2.8

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V4.1.3
  • V4.2.4
  • V1.5.3
  • V4.1.1

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-01 mostly match
prevents

Configuration management can enforce uniform HTTP parsing rules across intermediaries, directly mitigating inconsistent interpretation.

DE.CM-01 partial match
prevents

Network monitoring can detect smuggling attempts via anomalous HTTP traffic or logs, while eliminating the inconsistency directly aids detection of such events.

PR.IR-01 partial match
prevents

Network protections can enforce consistent HTTP proxy/firewall behavior to block smuggling, and removing the weakness helps prevent unauthorized access via request smuggling.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

detects

Security testing can detect HTTP request smuggling vulnerabilities in intermediary components.

degrades

Network security controls can enforce consistent HTTP parsing and proxy behavior that mitigates request smuggling.

degrades

Secure network services include hardening proxies and gateways against inconsistent HTTP interpretation.

prevents

Secure SDLC practices require threat modeling and testing for HTTP parsing inconsistencies in intermediaries.

prevents

Application security requirements can mandate strict HTTP message validation and canonicalization.

prevents

Secure architecture principles include consistent protocol handling and defense-in-depth for proxies.

References