CVE-2015-7977
ntp: restriction list NULL pointer dereference
Severity
ModerateRed Hat Product Security
CVSS 2.0
Review impact separately from score.
Published · January 20, 2016
Updated · May 13, 2026
Description
A NULL pointer dereference flaw was found in the way ntpd processed 'ntpdc reslist' commands that queried restriction lists with a large amount of entries. A remote attacker could potentially use this flaw to crash ntpd.
Statement
This issue affects the versions of ntp as shipped with Red Hat Enterprise Linux 5, 6, and 7. Red Hat Product Security has rated this issue as having Moderate security impact. A future update may address this issue in Red Hat Enterprise Linux 6 and 7. For additional information, refer to the Issue Severity Classification: https://access.redhat.com/security/updates/classification/.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
Keep the number of restriction list entries in ntp.conf lower than 500.
CVSS / CWE
CVSS 2.0 · 4.3AV:N/AC:M/Au:N/C:N/I:N/A:P
CWE-476 · NULL Pointer Dereference