CVE-2021-23846Network attack vector

Credential disclosure via plaintext HTTP login parameter

Published Jun 18, 2021 · Updated Sep 16, 2024

Cleartext credential transmission in Bosch B426 Firmware 03.01.0004 through 03.05.0003 allows man-in-the-middle attackers to steal passwords via HTTP. The login.cgi endpoint places the submitted user password in a plaintext HTTP parameter instead of protecting the login exchange with HTTPS. A user must submit credentials over HTTP while the attacker can intercept the network path; successful capture exposes the configuration password but does not by itself modify the device.

CVSS severity8.8
High
EPSS probability0.47%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cleartext credential transmission in Bosch B426 Firmware 03.01.0004 through 03.05.0003 allows man-in-the-middle attackers to steal passwords via HTTP. The login.cgi endpoint places the submitted user password in a plaintext HTTP parameter instead of protecting the login exchange with HTTPS. A user must submit credentials over HTTP while the attacker can intercept the network path; successful capture exposes the configuration password but does not by itself modify the device.

The record

CVE
CVE-2021-23846
Published
Jun 18, 2021
Updated
Sep 16, 2024
Vendor
Bosch Security Systems B.V.
Product
B426 Firmware
Classifications
CWE-319, T1557
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 18, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2024Record 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.

  1. Affected versionversion=03.01.0004
  2. Affected versionversion=03.02.002
  3. Affected versionversion=03.03.0009
  4. Affected versionversion=03.05.0003

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Bosch Security Systems B.V. · B426 Firmwareversion=03.01.0004; version=03.02.002; version=03.03.0009; version=03.05.0003

Published CVSS scores

8.0Zero Day InitiativeCVSS:3.0/AV:A/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
8.8Bosch PSIRTCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-319Cleartext Transmission of Sensitive Information
T1557Adversary-in-the-Middle

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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