How severe is CVE-2021-42129?

CVE-2021-42129 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-2021-42129 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 77% (100th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-42129?

CVE-2021-42129 affects Ivanti Avalanche. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-42129?

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-2021-42129 published?

CVE-2021-42129 was published on 2021-12-07 and last updated on 2026-06-17.

CVE-2021-42129

CVE-2021-42129 is a high-severity vulnerability in Ivanti Avalanche with a CVSS 3.x base score of 8.8. Its EPSS exploit-prediction score of 77% places it in the 100th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-77.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 6.5
EPSS exploit prediction: 77% (100th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-77
Affected product: Ivanti Avalanche
Published: 2021-12-07
Last modified: 2026-06-17

Description

A command injection vulnerability exists in Ivanti Avalanche before 6.3.3 allows an attacker with access to the Inforail Service to perform arbitrary command execution.

Frequently asked questions

What is CVE-2021-42129?: A command injection vulnerability exists in Ivanti Avalanche before 6.3.3 allows an attacker with access to the Inforail Service to perform arbitrary command execution.
How severe is CVE-2021-42129?: CVE-2021-42129 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-2021-42129 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 77% (100th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-42129?: CVE-2021-42129 affects Ivanti Avalanche. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-42129?: 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-2021-42129 published?: CVE-2021-42129 was published on 2021-12-07 and last updated on 2026-06-17.

References

https://forums.ivanti.com/s/article/Security-Alert-CVE-s-Addressed-in-Avalanche-6-3-3

Affected products (1)

cpe:2.3:a:ivanti:avalanche:*:*:*:*:*:*:*:*

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