CVE-2021-34587Network attack vector

Webserver crash via unbounded URL formatting

Published Apr 27, 2022 · Updated Sep 17, 2024

Stack-based buffer overflow in Bender CC612, CC613, ICC15xx, and ICC16xx firmware allows remote attackers to crash the webserver. The webserver passes a long request URL to sprintf as input for a stack variable without a published bound, causing a stack overwrite. Unauthenticated network access to the web interface is sufficient, and the documented consequence is interruption of the webserver rather than loss of electrical safety.

CVSS severity5.3
Medium
EPSS probability0.92%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack-based buffer overflow in Bender CC612, CC613, ICC15xx, and ICC16xx firmware allows remote attackers to crash the webserver. The webserver passes a long request URL to sprintf as input for a stack variable without a published bound, causing a stack overwrite. Unauthenticated network access to the web interface is sufficient, and the documented consequence is interruption of the webserver rather than loss of electrical safety.

The record

CVE
CVE-2021-34587
Published
Apr 27, 2022
Updated
Sep 17, 2024
Vendor
Bender GmbH & Co. KG
Product
CC612
Classifications
CWE-787, CWE-121, T0814
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 27, 2022CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.11.x <5.11.2
  2. Affected versionversion=5.12.x <5.12.5
  3. Affected versionversion=5.13.x <5.13.2
  4. Affected versionversion=5.20.x <5.20.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Bender GmbH & Co. KG · CC612version=5.11.x <5.11.2; version=5.12.x <5.12.5; version=5.13.x <5.13.2; version=5.20.x <5.20.2
Bender GmbH & Co. KG · ICC16xxversion=5.11.x <5.11.2; version=5.12.x <5.12.5; version=5.13.x <5.13.2; version=5.20.x <5.20.2
Bender GmbH & Co. KG · CC613version=5.11.x <5.11.2; version=5.12.x <5.12.5; version=5.13.x <5.13.2; version=5.20.x <5.20.2
Bender GmbH & Co. KG · ICC15xxversion=5.11.x <5.11.2; version=5.12.x <5.12.5; version=5.13.x <5.13.2; version=5.20.x <5.20.2

Published CVSS scores

5.3CERT@VDECVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
5.0NIST National Vulnerability DatabaseAV:N/AC:L/Au:N/C:N/I:N/A:P

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 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-787Out-of-bounds Write
CWE-121Stack-based Buffer Overflow
T0814Denial of Service

Public exploit references

No public exploit references are available in this record.

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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