How severe is CVE-2021-34735?

CVE-2021-34735 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-2021-34735 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (77th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-34735?

CVE-2021-34735 primarily affects Cisco Ata 190 Firmware. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-34735?

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-2021-34735 published?

CVE-2021-34735 was published on 2021-10-06 and last updated on 2026-06-17.

CVE-2021-34735

CVE-2021-34735 is a high-severity vulnerability in Cisco Ata 190 Firmware with a CVSS 3.x base score of 8.8. 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-770.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 7.8
EPSS exploit prediction: 2% (77th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-770
Affected product: Cisco Ata 190 Firmware
Published: 2021-10-06
Last modified: 2026-06-17

Description

Multiple vulnerabilities in the Cisco ATA 190 Series Analog Telephone Adapter Software could allow an attacker to perform a command injection attack resulting in remote code execution or cause a denial of service (DoS) condition on an affected device. For more information about these vulnerabilities, see the Details section of this advisory.

Frequently asked questions

What is CVE-2021-34735?: Multiple vulnerabilities in the Cisco ATA 190 Series Analog Telephone Adapter Software could allow an attacker to perform a command injection attack resulting in remote code execution or cause a denial of service (DoS) condition on an affected device. For more information about these vulnerabilities, see the Details section of this advisory.
How severe is CVE-2021-34735?: CVE-2021-34735 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-2021-34735 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (77th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-34735?: CVE-2021-34735 primarily affects Cisco Ata 190 Firmware. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-34735?: 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-2021-34735 published?: CVE-2021-34735 was published on 2021-10-06 and last updated on 2026-06-17.

References

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ata19x-multivuln-A4J57F3

Affected products (3)

cpe:2.3:o:cisco:ata_190_firmware:-:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ata_191_firmware:-:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ata_192_firmware:-:*:*:*:*:*:*:*

More vulnerabilities in Cisco Ata 190 Firmware

CVE-2021-34710 — High (CVSS 8.8): Multiple vulnerabilities in the Cisco ATA 190 Series Analog Telephone Adapter Software could allow an attacker to…
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CVE-2022-20690 — Medium (CVSS 5.3): Multiple vulnerabilities in the Cisco Discovery Protocol functionality of Cisco ATA 190 Series Analog Telephone Adapter…
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