VulnerabilityPublished 9 Oct 2024

CVE-2024-45160: lemonldap-ng · Incorrect Authorization

Affects lemonldap-ngSource CVE Database V5

Not known to be exploited · CVSS 9.1 Critical : upgrade to 2.19.2 as a priority.

Data as of 26 Oct 2026, 09:15 UTC

CVSS 3.1 base score

9.1Critical

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

EPSS: 0.5% chance of exploitation in 30 days – higher than 44% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 2.19.2

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
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: 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: 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 9 Oct 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 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 lemonldap-ng/lemonldap-ng to 2.19.2.

Affected software

Product	Affected	Fixed in
GitHublemonldap-ng/lemonldap-ng`pkg:github/lemonldap-ng/lemonldap-ng`Other threats	Affected =2.18 <2.19.2	Fixed in 2.19.2

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

AI-suggested

1. Immediately upgrade LemonLDAP::NG to version 2.19.2 or later, where the vulnerability is patched. 2. If upgrading is not immediately possible, implement strict network-level access controls to restrict access to the LemonLDAP::NG OAuth2 endpoints only to trusted clients and IP addresses. 3. Monitor authentication logs for unusual OAuth2 client authentication attempts, especially those with empty or missing client_password parameters. 4. Employ additional multi-factor authentication (MFA) mechanisms on top of OAuth2 client authentication to reduce the risk of unauthorized access. 5. Conduct a thorough audit of all OAuth2 clients registered in LemonLDAP::NG to ensure no unauthorized clients exist. 6. Review and tighten OAuth2 client secret management policies to prevent weak or empty secrets. 7. Consider deploying web application firewalls (WAFs) with rules to detect and block requests missing client_password parameters. 8. Educate security teams about this vulnerability to ensure rapid detection and response to potential exploitation attempts.

Description

Incorrect credential validation in LemonLDAP::NG 2.18.x and 2.19.x before 2.19.2 allows attackers to bypass OAuth2 client authentication via an empty client_password parameter (client secret).

Impact

The vulnerability allows attackers to bypass OAuth2 client authentication, leading to unauthorized access to sensitive systems and data. This can compromise confidentiality by exposing protected information and integrity by enabling attackers to act as legitimate clients, potentially manipulating or accessing resources without authorization. Since the flaw does not require privileges or user interaction, it can be exploited remotely and easily, increasing the attack surface. Organizations relying on LemonLDAP::NG for authentication in critical infrastructure, government, or enterprise environments face risks of data breaches, unauthorized system access, and potential lateral movement within networks. The absence of availability impact means systems remain operational but compromised. The critical severity and network exploitability elevate the urgency for mitigation to prevent potential large-scale breaches or espionage activities.

CWE-863Incorrect Authorization (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #17OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.
Architecture and Design
Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) to enforce the roles at the appropriate boundaries.
Architecture and Design
Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
OWASP Cheat Sheets
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.8 (opens in a new tab)
V13.4.2 (opens in a new tab)
V7.2.2 (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, 06:52 UTC

WeaknessesCWE-863

Technical details

References

Community reviews

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