ESP-IDF web_server basic auth bypass using empty or incomplete Authorization header
ESPHome is a system to control microcontrollers remotely through Home Automation systems. In version 2025.8.0 in the ESP-IDF platform, ESPHome's web_server authentication check can pass incorrectly when the client-supplied base64-encoded Authorization value is empty or is a substring of the correct value. This allows access to web_server functionality (including OTA, if enabled) without knowing any information about the correct username or password. This issue has been patched in version 2025.8.1.
- Published
- Sep 1, 2025
- Updated
- Jun 17, 2026
- EPSS
- 1.6% · 74th percentile
- CWE
- CWE-303
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Report tools
Action score
32
Monitor
Low priority for now.
- CVSS
- 32 / 40 · 8.1 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 1.6%
CISA SSVC decision
- Exploitation
- proof of concept
- Automatable
- no
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · GitHub_M
- 8.1
- NVD has not scored this yet; the score shown is the CNA’s.
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
| Vendor | Product | CPE |
|---|---|---|
| esphome | esphome firmware | cpe:2.3:o:esphome:esphome_firmware |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- esphome esphome firmware2025.8.0
Versions reported by the vendor
Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.
esphome esphome
- = 2025.8.0affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| PyPI | esphome | before 2025.8.1 | 2025.8.1 |
Same product
esphome: all recordsOther highest-scoring records for the same primary product.
- CVE-2021-41104web_server allows OTA update without checking user defined basic auth username & password30Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| esphome esphome | 2025.8.1 · description | Vendor (CNA) |
| PyPI:esphome | 2025.8.1 | Package registry (OSV) |
Exploit status
Proof of concept available
A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.
Evidence
- Nuclei detection template ×1
Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.
| Source | Kind | Date |
|---|---|---|
| Nuclei detection template | Nuclei template CVE-2025-57808 | — |
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Someone on the same network segment can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- none
- Attack vector
- Adjacent
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- None
Weakness class (CWE)
CWE-303 · Incorrect Implementation of Authentication AlgorithmCVSS vector
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
ATT&CK techniques
—
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Vendor advisories and official records. Exploit/PoC links are deliberately left out.