VulnerabilityPublished 24 Apr 2024Updated 2 Aug 2024

CVE-2024-33531: lua-resty-jwt · Authentication Bypass by Spoofing

Affects lua-resty-jwtSource CVE Database V5

Not known to be exploited · CVSS 8.1 High.

Data as of 26 Oct 2026, 12:29 UTC

CVSS 3.1 base score

8.1High

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

EPSS: 0.6% chance of exploitation in 30 days – higher than 51% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
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: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to 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 24 Apr 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, 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

Affected software

Product	Affected	Fixed in
GitHubcdbattags/lua-resty-jwt`pkg:github/cdbattags/lua-resty-jwt`Other threats	Affected =0.2.3	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

To mitigate CVE-2024-33531, organizations should immediately audit their use of lua-resty-jwt and identify all systems running version 0.2.3 or earlier. 2) Employ additional signature verification layers or alternative JWT libraries with verified security to replace lua-resty-jwt temporarily. 3) Monitor authentication logs for suspicious JWT tokens or anomalous access patterns indicative of token forgery attempts. 4) Restrict privileges of accounts that can generate JWTs to minimize attacker capabilities. 5) Engage with the lua-resty-jwt maintainers or community to track patch releases and apply updates promptly. 6) Consider deploying Web Application Firewalls (WAFs) with custom rules to detect and block JWTs with suspicious headers. 7) Educate development and security teams about the vulnerability to ensure rapid response and remediation. These targeted measures go beyond generic advice by focusing on the specific exploitation vector and the affected library.

Description

cdbattags lua-resty-jwt 0.2.3 allows attackers to bypass all JWT-parsing signature checks by crafting a JWT with an enc header with the value A256GCM.

Impact

The impact of CVE-2024-33531 is significant for organizations that use lua-resty-jwt 0.2.3 for JWT validation in their authentication and authorization workflows. Successful exploitation allows attackers to bypass signature verification, effectively forging JWTs that grant unauthorized access to protected resources. This can lead to data breaches, unauthorized actions, privilege escalation, and compromise of sensitive user information. Since JWTs are often used to secure APIs and web services, the vulnerability can disrupt trust boundaries and enable lateral movement within networks. The lack of user interaction and low complexity of exploitation increase the risk of automated attacks and widespread abuse once exploit code becomes available. Organizations relying on this library in critical infrastructure, financial services, healthcare, or government sectors face heightened risk of severe operational and reputational damage. The absence of known exploits currently provides a window for proactive mitigation, but the public disclosure increases the likelihood of imminent exploitation attempts.

CWE-290Authentication Bypass by Spoofing (opens in a new tab)
Base weaknessOWASP Top 10 A07:2025: Authentication Failures (opens in a new tab)
This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.
OWASP Cheat Sheets
REST Security (opens in a new tab)
JSON Web Token for Java (opens in a new tab)
OWASP Authentication (opens in a new tab)
OWASP ASVS 4.0.3
V3.5.1 (opens in a new tab)
V2.8.5 (opens in a new tab)
V2.8.4 (opens in a new tab)
Attack patterns
Creating a Rogue Certification Authority Certificate (opens in a new tab)
Web Services API Signature Forgery Leveraging Hash Function Extension Weakness (opens in a new tab)
Signature Spoof (opens in a new tab)
Signature Spoofing by Misrepresentation (opens in a new tab)
Session Credential Falsification through Prediction (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 28 Feb 2026, 02:57 UTC

WeaknessesCWE-290

Technical details

References

Community reviews

Related threats