How severe is CVE-2021-28911?

CVE-2021-28911 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-28911 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-28911?

CVE-2021-28911 affects Bab-technologie Eibport Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-28911?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2021-28911 published?

CVE-2021-28911 was published on 2021-09-09 and last updated on 2026-06-17.

CVE-2021-28911

CVE-2021-28911 is a critical-severity vulnerability in Bab-technologie Eibport Firmware with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-307.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 10.0
EPSS exploit prediction: 2% (74th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-307
Affected product: Bab-technologie Eibport Firmware
Published: 2021-09-09
Last modified: 2026-06-17

Description

BAB TECHNOLOGIE GmbH eibPort V3 prior version 3.9.1 allow unauthenticated attackers access to /tmp path which contains some sensitive data (e.g. device serial number). Having those info, a possible loginId can be self-calculated in a brute force attack against BMX interface. This is usable and part of an attack chain to gain SSH root access.

Frequently asked questions

What is CVE-2021-28911?: BAB TECHNOLOGIE GmbH eibPort V3 prior version 3.9.1 allow unauthenticated attackers access to /tmp path which contains some sensitive data (e.g. device serial number). Having those info, a possible loginId can be self-calculated in a brute force attack against BMX interface. This is usable and part of an attack chain to gain SSH root access.
How severe is CVE-2021-28911?: CVE-2021-28911 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-28911 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-28911?: CVE-2021-28911 affects Bab-technologie Eibport Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-28911?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-28911 published?: CVE-2021-28911 was published on 2021-09-09 and last updated on 2026-06-17.

References

https://psytester.github.io/CVE-2021-28911

Affected products (1)

cpe:2.3:o:bab-technologie:eibport_firmware:*:*:*:*:*:*:*:*

More vulnerabilities in Bab-technologie Eibport Firmware

CVE-2021-28913 — Critical (CVSS 9.8): BAB TECHNOLOGIE GmbH eibPort V3 prior version 3.9.1 allow unauthenticated attackers access to /webif/SecurityModule to…
CVE-2021-28909 — Critical (CVSS 9.8): BAB TECHNOLOGIE GmbH eibPort V3 prior version 3.9.1 allow unauthenticated attackers to access uncontrolled the login…
CVE-2021-28910 — High (CVSS 7.5): BAB TECHNOLOGIE GmbH eibPort V3 prior version 3.9.1 contains basic SSRF vulnerability. It allow unauthenticated…
CVE-2020-24573 — High (CVSS 7.5): BAB TECHNOLOGIE GmbH eibPort V3 prior to 3.8.3 devices allow denial of service (Uncontrolled Resource Consumption) via…
CVE-2021-28912 — High (CVSS 7.2): BAB TECHNOLOGIE GmbH eibPort V3. Each device has its own unique hard coded and weak root SSH key passphrase known as…
CVE-2021-28914 — Medium (CVSS 6.5): BAB TECHNOLOGIE GmbH eibPort V3 prior version 3.9.1 allow the user to set a weak password because the strength is shown…

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