CVE-2021-23845Network attack vector

Session hijacking via hard-coded session token

Published Jun 18, 2021 · Updated Sep 16, 2024

Improper access control in Bosch B426-family firmware allows remote attackers to hijack an active web configuration session. The lgs.cgi module accepts a hard-coded session token instead of validating a session-specific credential. Network access and an active user session are required; exploitation exposes configuration pages without login credentials.

CVSS severity8.0
High
EPSS probability0.84%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper access control in Bosch B426-family firmware allows remote attackers to hijack an active web configuration session. The lgs.cgi module accepts a hard-coded session token instead of validating a session-specific credential. Network access and an active user session are required; exploitation exposes configuration pages without login credentials.

The record

CVE
CVE-2021-23845
Published
Jun 18, 2021
Updated
Sep 16, 2024
Vendor
Bosch Security Systems B.V.
Product
B426-M Firmware
Classifications
CWE-284, T1190
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=unspecified <03.10

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Bosch Security Systems B.V. · B426-M Firmwareversion=unspecified <03.10
Bosch Security Systems B.V. · B426 Firmwareversion=unspecified <03.08
Bosch Security Systems B.V. · B426-CN/B429-CN Firmwareversion=unspecified <03.08

Published CVSS scores

8.0Robert Bosch GmbHCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
8.8NIST NVDCVSS: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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-284Improper Access Control
T1190Exploit Public-Facing Application

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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