How severe is CVE-2020-27743?

CVE-2020-27743 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-2020-27743 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (75th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-27743?

CVE-2020-27743 affects Pam Tacplus Project Pam Tacplus. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-27743?

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-2020-27743 published?

CVE-2020-27743 was published on 2020-10-26 and last updated on 2026-06-17.

CVE-2020-27743

CVE-2020-27743 is a critical-severity vulnerability in Pam Tacplus Project Pam Tacplus 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-330.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 2% (75th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-330
Affected product: Pam Tacplus Project Pam Tacplus
Published: 2020-10-26
Last modified: 2026-06-17

Description

libtac in pam_tacplus through 1.5.1 lacks a check for a failure of RAND_bytes()/RAND_pseudo_bytes(). This could lead to use of a non-random/predictable session_id.

Frequently asked questions

What is CVE-2020-27743?: libtac in pam_tacplus through 1.5.1 lacks a check for a failure of RAND_bytes()/RAND_pseudo_bytes(). This could lead to use of a non-random/predictable session_id.
How severe is CVE-2020-27743?: CVE-2020-27743 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-2020-27743 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (75th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-27743?: CVE-2020-27743 affects Pam Tacplus Project Pam Tacplus. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-27743?: 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-2020-27743 published?: CVE-2020-27743 was published on 2020-10-26 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:pam_tacplus_project:pam_tacplus:*:*:*:*:*:*:*:*

More vulnerabilities in Pam Tacplus Project Pam Tacplus

CVE-2016-20014 — Critical (CVSS 9.8): In pam_tacplus.c in pam_tacplus before 1.4.1, pam_sm_acct_mgmt does not zero out the arep data structure.
CVE-2020-13881 — High (CVSS 7.5): In support.c in pam_tacplus 1.3.8 through 1.5.1, the TACACS+ shared secret gets logged via syslog if the DEBUG loglevel…

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