How severe is CVE-2021-20618?

CVE-2021-20618 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-2021-20618 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (87th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-20618?

CVE-2021-20618 primarily affects Acmailer. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-20618?

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-2021-20618 published?

CVE-2021-20618 was published on 2021-01-14 and last updated on 2026-06-17.

CVE-2021-20618

CVE-2021-20618 is a critical-severity vulnerability in Acmailer 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-269.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 10.0
EPSS exploit prediction: 3% (87th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-269
Affected product: Acmailer
Published: 2021-01-14
Last modified: 2026-06-17

Description

Privilege chaining vulnerability in acmailer ver. 4.0.2 and earlier, and acmailer DB ver. 1.1.4 and earlier allows remote attackers to bypass authentication and to gain an administrative privilege which may result in obtaining the sensitive information on the server via unspecified vectors.

Frequently asked questions

What is CVE-2021-20618?: Privilege chaining vulnerability in acmailer ver. 4.0.2 and earlier, and acmailer DB ver. 1.1.4 and earlier allows remote attackers to bypass authentication and to gain an administrative privilege which may result in obtaining the sensitive information on the server via unspecified vectors.
How severe is CVE-2021-20618?: CVE-2021-20618 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-2021-20618 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (87th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-20618?: CVE-2021-20618 primarily affects Acmailer. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-20618?: 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-2021-20618 published?: CVE-2021-20618 was published on 2021-01-14 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:acmailer:acmailer:*:*:*:*:*:*:*:*
cpe:2.3:a:acmailer:acmailer_db:*:*:*:*:*:*:*:*

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