How severe is CVE-2021-28374?

CVE-2021-28374 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2021-28374 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (66th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-28374?

CVE-2021-28374 primarily affects Debian Courier-authlib. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-28374?

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-2021-28374 published?

CVE-2021-28374 was published on 2021-03-15 and last updated on 2026-06-17.

CVE-2021-28374

CVE-2021-28374 is a high-severity vulnerability in Debian Courier-authlib with a CVSS 3.x base score of 7.5. 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-732.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 1% (66th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-732
Affected product: Debian Courier-authlib
Published: 2021-03-15
Last modified: 2026-06-17

Description

The Debian courier-authlib package before 0.71.1-2 for Courier Authentication Library creates a /run/courier/authdaemon directory with weak permissions, allowing an attacker to read user information. This may include a cleartext password in some configurations. In general, it includes the user's existence, uid and gids, home and/or Maildir directory, quota, and some type of password information (such as a hash).

Frequently asked questions

What is CVE-2021-28374?: The Debian courier-authlib package before 0.71.1-2 for Courier Authentication Library creates a /run/courier/authdaemon directory with weak permissions, allowing an attacker to read user information. This may include a cleartext password in some configurations. In general, it includes the user's existence, uid and gids, home and/or Maildir directory, quota, and some type of password information (such as a hash).
How severe is CVE-2021-28374?: CVE-2021-28374 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2021-28374 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (66th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-28374?: CVE-2021-28374 primarily affects Debian Courier-authlib. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-28374?: 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-2021-28374 published?: CVE-2021-28374 was published on 2021-03-15 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:debian:courier-authlib:*:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*

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