Identifier disclosure via unenforced ACME transport encryption
Published Aug 7, 2025 · Updated Aug 7, 2025
Cleartext ACME communication in go-acme Lego 4.25.1 and earlier allows man-in-the-middle attackers to read request and account identifiers. The acme/api internal sender's NewDoer path accepted operator-configured discovery URLs and CA-returned directory or order URLs without rejecting HTTP. Exploitation requires an HTTP endpoint supplied by the operator or CA and a privileged network position; only ACME data disclosure was demonstrated.
Summary
What happened
Cleartext ACME communication in go-acme Lego 4.25.1 and earlier allows man-in-the-middle attackers to read request and account identifiers. The acme/api internal sender's NewDoer path accepted operator-configured discovery URLs and CA-returned directory or order URLs without rejecting HTTP. Exploitation requires an HTTP endpoint supplied by the operator or CA and a privileged network position; only ACME data disclosure was demonstrated.
The record
- CVE
- CVE-2025-54799
- Published
- Aug 7, 2025
- Updated
- Aug 7, 2025
- Vendor
- go-acme
- Product
- Lego
- Classifications
- CWE-319, T1040
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 7, 2025CVE publishedPublication date reported by the CVE source.
- Aug 7, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 4.25.2
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- http_acme_test.go HTTPS-enforcement reproductionproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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