CVSS2
Attack Vector
LOCAL
Attack Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:L/AC:M/Au:N/C:C/I:C/A:C
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
HIGH
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
EPSS
Percentile
26.7%
In the cron package through 3.0pl1-128 on Debian, and through
3.0pl1-128ubuntu2 on Ubuntu, the postinst maintainer script allows for
group-crontab-to-root privilege escalation via symlink attacks against
unsafe usage of the chown and chmod programs.
Author | Note |
---|---|
jj | This appears to be mitigated by kernel symlink restrictions. The crontabs dir has the sticky bit set drwx-wx–T root crontab crontabs which means symlinks within the dir must have the same uid as the target. It is still possible that a cron package update could trigger this race. |
seth-arnold | I believe that actually exploiting the bug requires updating the cron package. So long as there’s no updates for cron, the vulnerable code doesn’t run. So if we find a second bug in cron then we really should fix the race condition at the same time, but so long as we don’t push a cron update, the vulnerable code just plain doesn’t run. the patch just narrows the time window for the race condition. |
bugs.debian.org/864466
www.openwall.com/lists/oss-security/2017/06/08/3
launchpad.net/bugs/cve/CVE-2017-9525
nvd.nist.gov/vuln/detail/CVE-2017-9525
security-tracker.debian.org/tracker/CVE-2017-9525
ubuntu.com/security/notices/USN-5259-1
ubuntu.com/security/notices/USN-5259-2
ubuntu.com/security/notices/USN-5259-3
www.cve.org/CVERecord?id=CVE-2017-9525
CVSS2
Attack Vector
LOCAL
Attack Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:L/AC:M/Au:N/C:C/I:C/A:C
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
HIGH
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
EPSS
Percentile
26.7%