Lemonldap: Improper Authentication
CVE-2023-28862 is a critical-severity improper authentication vulnerability in Lemonldap from Lemonldap-ng, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 2.16.1 as the first without the flaw, so updating Lemonldap to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.96% chance of exploitation within 30 days, higher than 62% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Lemonldap to 2.16.1 or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Lemonldap-ng | Lemonldap | before 2.16.1 | 2.16.1 |
Version data comes from NVD's product matching. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 9.8 | Critical | NVD |
| CVSS 3.1 | 9.8 | Critical | CISA (ADP) |
Official description
An issue was discovered in LemonLDAP::NG before 2.16.1. Weak session ID generation in the AuthBasic handler and incorrect failure handling during a password check allow attackers to bypass 2FA verification. Any plugin that tries to deny session creation after the store step does not deny an AuthBasic session.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Authentication
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
How developers prevent this class of flaw
- Use an authentication framework or library such as the OWASP ESAPI Authentication feature.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- gitlab.ow2.org/lemonldap-ng/lemonldap-ng/-/issues/2896Exploit, Issue Tracking
- gitlab.ow2.org/lemonldap-ng/lemonldap-ng/-/releases/v2.16.1Release Notes
Other references
Recent Improper Authentication vulnerabilities
- 9.8 Critical severity
- 9.8 Critical severity
- 8.8 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 7.5 High severity
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