VulnerabilityPublished 19 Sep 2024Updated 3 Nov 2025

CVE-2024-45614: puma · Insecure Direct Object Reference

Affects pumaSource GCVE Database

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Not known to be exploited · CVSS 5.4 Medium : upgrade to 6.4.3 or 5.6.9 when convenient.

Data as of 30 Oct 2026, 02:22 UTC

CVSS 3.1 base score

5.4Medium

How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none

CVSS scores by source
CNA (GitHub_M)	CVSS 3.1	5.4

Patch: Available – fixed in 6.4.3, 5.6.9

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N

Attack Vector: Network
Attack Complexity: High
Privileges Required: None
User Interaction: None
Scope: Changed
Confidentiality: Low
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 19 Sep 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade puma to 6.4.3 or 5.6.9.

Affected software

Product	Affected	Fixed in
puma puma	Affected >=6.0.0 <6.4.3 <5.6.9	Fixed in 6.4.3 5.6.9

AI-suggested

Upgrade Puma to version 6.4.3 or 5.6.9 or later, where the vulnerability is fixed by discarding underscore headers when the non-underscore version exists. Until upgraded, users should not implicitly trust proxy-set headers for security decisions. Additionally, if using Nginx as a proxy, enable the underscores_in_headers configuration to discard headers containing underscores as a temporary mitigation.

Description

CVE-2024-45614 is an authorization bypass vulnerability in the Puma Ruby/Rack web server. Affected versions allow clients to override proxy-set headers (like X-Forwarded-For) by sending underscore variants (e.g., X-Forwarded_For). This can lead to trusting manipulated headers instead of those set by trusted proxies. Versions 6.4.3 and 5.6.9 fix this by discarding headers with underscores when the non-underscore version exists. Users relying on proxy headers for security should upgrade immediately or use proxy-level mitigations such as Nginx's underscores_in_headers setting.

Impact

The vulnerability allows an attacker to bypass authorization checks that rely on proxy-set headers by sending specially crafted headers with underscores to override trusted proxy values. This can lead to incorrect client IP identification or other security decisions based on manipulated headers. The impact is limited to scenarios where applications implicitly trust proxy headers for security purposes. The CVSS score is 5.4 (medium severity), indicating limited but meaningful confidentiality and integrity impact without availability impact.

Summary

Puma versions >=6.0.0 <6.4.3 and <5.6.9 are vulnerable to an authorization bypass due to improper handling of HTTP headers with underscores. Clients can send headers with underscores that override the values set by intermediate proxies in standard headers like X-Forwarded-For. This allows attackers to manipulate proxy-trusted headers, potentially bypassing security controls that rely on these headers. The issue is fixed in Puma versions 6.4.3 and 5.6.9 by discarding underscore headers if the corresponding non-underscore header is present. Nginx users can mitigate by enabling the underscores_in_headers configuration to discard such headers at the proxy level.

CWE-639Authorization Bypass Through User-Controlled Key (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #24OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.
Architecture and Design
For each and every data access, ensure that the user has sufficient privilege to access the record that is being requested.
Architecture and Design · Implementation
Make sure that the key that is used in the lookup of a specific user's record is not controllable externally by the user or that any tampering can be detected.
Architecture and Design
Use encryption in order to make it more difficult to guess other legitimate values of the key or associate a digital signature with the key so that the server can verify that there has been no tampering.
OWASP Cheat Sheets
Access Control (opens in a new tab)
Authorization Testing Automation (opens in a new tab)
Cross-Site Request Forgery Prevention (opens in a new tab)
Insecure Direct Object Reference Prevention (opens in a new tab)
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V4.1.2 (opens in a new tab)
V4.2.1 (opens in a new tab)
V8.3.8 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 30 Oct 2026, 02:22 UTC

Public exploits and detectionGitHub proofs of concept

WeaknessesCWE-639

Technical details

References

Community reviews

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