VYPR
Unrated severityNVD Advisory· Published Nov 5, 2019· Updated Aug 6, 2024

CVE-2016-4983

CVE-2016-4983

Description

A postinstall script in the dovecot rpm allows local users to read the contents of newly created SSL/TLS key files.

AI Insight

LLM-synthesized narrative grounded in this CVE's description and references.

Affected products

10

Patches

Vulnerability mechanics

Root cause

"The postinstall script for the dovecot rpm creates SSL/TLS key files before setting restrictive file permissions."

Attack vector

A local user can read the contents of newly created SSL/TLS key files. This exposure occurs between the time the file is created and the `chmod 600` command is executed by the rpm postinstall script. The vulnerability is present in older RHEL 4 versions and later versions utilizing `/usr/libexec/dovecot/mkcert.sh` [ref_id=1].

Affected code

The vulnerability lies within the rpm postinstall scripts for the dovecot package. In older versions, this is a direct script snippet creating `/usr/share/ssl/certs/dovecot.pem` and `/usr/share/ssl/private/dovecot.pem`. Later versions utilize `/usr/libexec/dovecot/mkcert.sh` to generate `/etc/pki/dovecot/certs/dovecot.pem` and `/etc/pki/dovecot/private/dovecot.pem` [ref_id=1].

What the fix does

The advisory suggests setting `umask 077` before the file creation process to ensure that newly created files have restrictive permissions from the outset [ref_id=1]. Additionally, it recommends that secrets should be unique per instance or install, and generated at runtime rather than during package installation to prevent shared secrets across container or image instances [ref_id=1].

Preconditions

  • authThe attacker must have local user access to the system where dovecot is being installed or updated.

Generated on Jun 3, 2026. Inputs: CWE entries + fix-commit diffs from this CVE's patches. Citations validated against bundle.

References

3

News mentions

0

No linked articles in our index yet.