CVE-2020-13881Network attack vector

TACACS+ secret disclosure via DEBUG syslog logging

Published Jun 6, 2020 · Updated Aug 4, 2024

Information disclosure in pam_tacplus 1.3.8 through 1.5.1 allows remote attackers to expose the TACACS+ shared secret via syslog. The _pam_parse function in support.c formats tac_srv[n].key into a LOG_DEBUG message instead of masking the configured secret. Exposure requires DEBUG logging with journald, which preserves the message and reveals the shared authentication secret to parties able to read the journal.

CVSS severity7.5
High
EPSS probability1.67%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in pam_tacplus 1.3.8 through 1.5.1 allows remote attackers to expose the TACACS+ shared secret via syslog. The _pam_parse function in support.c formats tac_srv[n].key into a LOG_DEBUG message instead of masking the configured secret. Exposure requires DEBUG logging with journald, which preserves the message and reveals the shared authentication secret to parties able to read the journal.

The record

CVE
CVE-2020-13881
Published
Jun 6, 2020
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-532, T1552.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 6, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
4.3NIST NVDAV:N/AC:M/Au:N/C:P/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-532Insertion of Sensitive Information into Log File
T1552.001Unsecured Credentials: Credentials In Files

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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