CVE-2020-28935 (Medium) detected in src0aecda14650f9fce8577e43d2a403385b5fa5bcf

[mend-for-github-com[bot]]

CVE-2020-28935 - Medium Severity Vulnerability

Vulnerable Library - src0aecda14650f9fce8577e43d2a403385b5fa5bcf

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Library home page: https://github.com/openbsd/src.git

Vulnerable Source Files (2)

/usr.sbin/unbound/daemon/unbound.c /usr.sbin/unbound/daemon/unbound.c

Vulnerability Details

NLnet Labs Unbound, up to and including version 1.12.0, and NLnet Labs NSD, up to and including version 4.3.3, contain a local vulnerability that would allow for a local symlink attack. When writing the PID file, Unbound and NSD create the file if it is not there, or open an existing file for writing. In case the file was already present, they would follow symlinks if the file happened to be a symlink instead of a regular file. An additional chown of the file would then take place after it was written, making the user Unbound/NSD is supposed to run as the new owner of the file. If an attacker has local access to the user Unbound/NSD runs as, she could create a symlink in place of the PID file pointing to a file that she would like to erase. If then Unbound/NSD is killed and the PID file is not cleared, upon restarting with root privileges, Unbound/NSD will rewrite any file pointed at by the symlink. This is a local vulnerability that could create a Denial of Service of the system Unbound/NSD is running on. It requires an attacker having access to the limited permission user Unbound/NSD runs as and point through the symlink to a critical file on the system.

Publish Date: 2020-12-07

URL: CVE-2020-28935

CVSS 3 Score Details (5.5)

Base Score Metrics: - Exploitability Metrics: - Attack Vector: Local - Attack Complexity: Low - Privileges Required: Low - User Interaction: None - Scope: Unchanged - Impact Metrics: - Confidentiality Impact: None - Integrity Impact: None - Availability Impact: High

For more information on CVSS3 Scores, click here.

Suggested Fix

Type: Upgrade version

Origin: https://bugzilla.redhat.com/show_bug.cgi?id=1878761

Release Date: 2020-12-07

Fix Resolution: release-1.13.0rc1

[mend-for-github-com[bot]]

:heavy_check_mark: This issue was automatically closed by Mend because the vulnerable library in the specific branch(es) was either marked as ignored or it is no longer part of the Mend inventory.

[mend-for-github-com[bot]]

:information_source: This issue was automatically re-opened by Mend because the vulnerable library in the specific branch(es) has been detected in the Mend inventory.