CVE-2020-13776

2020-06-0300:00:00

ubuntu.com

6.7 Medium

CVSS3

Attack Vector

LOCAL

Attack Complexity

HIGH

Privileges Required

LOW

User Interaction

REQUIRED

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H

6.2 Medium

CVSS2

Access Vector

LOCAL

Access Complexity

HIGH

Authentication

NONE

Confidentiality Impact

COMPLETE

Integrity Impact

COMPLETE

Availability Impact

COMPLETE

AV:L/AC:H/Au:N/C:C/I:C/A:C

0.0004 Low

EPSS

Percentile

11.7%

JSON

systemd through v245 mishandles numerical usernames such as ones composed
of decimal digits or 0x followed by hex digits, as demonstrated by use of
root privileges when privileges of the 0x0 user account were intended.
NOTE: this issue exists because of an incomplete fix for CVE-2017-1000082.

Bugs

<https://github.com/systemd/systemd/issues/15985>

Notes

Author	Note
mdeslaur	The administrator would have to create a systemd service unit with a numerical username or a username starting with 0x as a User= value, and that particular userid would need to exist on the system. Setting priority to low due to this unlikely scenario. Fixing this requires an extensive backport that refactors integer parsing in systemd and the risk of regressions stemming from the behavioural change outweighs the severity of this issue. We will not be fixing this issue in stable Ubuntu releases.

Author

Note

mdeslaur

The administrator would have to create a systemd service unit with a numerical username or a username starting with 0x as a User= value, and that particular userid would need to exist on the system. Setting priority to low due to this unlikely scenario. Fixing this requires an extensive backport that refactors integer parsing in systemd and the risk of regressions stemming from the behavioural change outweighs the severity of this issue. We will not be fixing this issue in stable Ubuntu releases.