How severe is CVE-2021-42912?

CVE-2021-42912 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-42912 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 10% (96th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-42912?

CVE-2021-42912 primarily affects Fiberhome An5506-01-a Firmware. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-42912?

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

When was CVE-2021-42912 published?

CVE-2021-42912 was published on 2021-12-16 and last updated on 2026-07-09.

CVE-2021-42912

CVE-2021-42912 is a high-severity vulnerability in Fiberhome An5506-01-a Firmware with a CVSS 3.x base score of 8.8. Its EPSS exploit-prediction score of 10% places it in the 96th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-78.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 9.0
EPSS exploit prediction: 10% (96th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-78
Affected product: Fiberhome An5506-01-a Firmware
Published: 2021-12-16
Last modified: 2026-07-09

Description

FiberHome ONU GPON AN5506-04-F RP2617 is affected by an OS command injection vulnerability. This vulnerability allows the attacker, once logged in, to send commands to the operating system as the root user via the ping diagnostic tool, bypassing the IP address field, and concatenating OS commands with a semicolon.

Frequently asked questions

What is CVE-2021-42912?: FiberHome ONU GPON AN5506-04-F RP2617 is affected by an OS command injection vulnerability. This vulnerability allows the attacker, once logged in, to send commands to the operating system as the root user via the ping diagnostic tool, bypassing the IP address field, and concatenating OS commands with a semicolon.
How severe is CVE-2021-42912?: CVE-2021-42912 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-42912 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 10% (96th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-42912?: CVE-2021-42912 primarily affects Fiberhome An5506-01-a Firmware. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-42912?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-42912 published?: CVE-2021-42912 was published on 2021-12-16 and last updated on 2026-07-09.

References

Affected products (8)

cpe:2.3:o:fiberhome:an5506-01-a_firmware:rp0509:*:*:*:*:*:*:*
cpe:2.3:o:fiberhome:an5506-01-b_firmware:rp2610:*:*:*:*:*:*:*
cpe:2.3:o:fiberhome:an5506-02-b_firmware:rp2520:*:*:*:*:*:*:*
cpe:2.3:o:fiberhome:an5506-02-b_firmware:rp2521:*:*:*:*:*:*:*
cpe:2.3:o:fiberhome:an5506-02-b_firmware:rp2603:*:*:*:*:*:*:*
cpe:2.3:o:fiberhome:an5506-04-b_firmware:rp2510:*:*:*:*:*:*:*
cpe:2.3:o:fiberhome:an5506-04-f_firmware:rp2617:*:*:*:*:*:*:*
cpe:2.3:o:fiberhome:aan5506-04-g2g_firmware:rp2560:*:*:*:*:*:*:*

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