Apache HttpComponents: Improper Certificate Validation
CVE-2025-27820 is a high-severity improper certificate validation vulnerability in Apache HttpComponents from Apache, with a CVSS 3.1 base score of 7.5 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 5.4.3 as the first without the flaw, so updating Apache HttpComponents to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.97% chance of exploitation within 30 days, higher than 62% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Apache HttpComponents to 5.4.3 or a later version.
- Update Httpclient to 5.4.3 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 |
|---|---|---|---|
| Apache | Apache HttpComponents | 5.4.0 up to, but not including, 5.4.3 | 5.4.3 |
| Apache | Httpclient | 5.4 up to, but not including, 5.4.3 | 5.4.3 |
| NetApp | Ontap Tools | 10 | Not stated |
Version data comes from the organisation that assigned the CVE. 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
- NoneNo data is disclosed.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N. Scored by CISA (ADP).
Official description
A bug in PSL validation logic in Apache HttpClient 5.4.x disables domain checks, affecting cookie management and host name verification. Discovered by the Apache HttpClient team. Fixed in the 5.4.3 release
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Certificate Validation
The product does not validate, or incorrectly validates, a certificate.
How developers prevent this class of flaw
- Certificates should be carefully managed and checked to assure that data are encrypted with the intended owner's public key.
- If certificate pinning is being used, ensure that all relevant properties of the certificate are fully validated before the certificate is pinned, including the hostname.
More Improper Certificate Validation vulnerabilities (CWE-295)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- github.com/apache/httpcomponents-client/pull/574Issue Tracking
- github.com/apache/httpcomponents-client/pull/621Issue Tracking
- lists.apache.org/thread/55xhs40ncqv97qvoocok44995xp5kqn8Mailing List
Third-party and government advisories
- security.netapp.com/advisory/ntap-20250516-0003/Third Party Advisory
Other references
Recent Improper Certificate Validation vulnerabilities
- 8.1 High severity
- 7.5 High severity
- 7.2 High severity
- 8.7 High severity
- 8.8 High severity
- 8.8 High severity
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