CVE-2019-18276

Current Description

An issue was discovered in disable_priv_mode in shell.c in GNU Bash through 5.0 patch 11. By default, if Bash is run with its effective UID not equal to its real UID, it will drop privileges by setting its effective UID to its real UID. However, it does so incorrectly. On Linux and other systems that support "saved UID" functionality, the saved UID is not dropped. An attacker with command execution in the shell can use "enable -f" for runtime loading of a new builtin, which can be a shared object that calls setuid() and therefore regains privileges. However, binaries running with an effective UID of 0 are unaffected.

Basic Data

Published	November 28, 2019
Last Modified	April 30, 2020
Assigner	cve@mitre.org
Data Type	CVE
Data Format	MITRE
Data Version	4.0
Problem Type	CWE-273
CVE Data Version	4.0

Base Metric V2

CVSS 2 - Version	2.0
CVSS 2 - Vector String	AV:L/AC:L/Au:N/C:C/I:C/A:C
CVSS 2 - Access Vector	LOCAL
CVSS 2 - Access Complexity	LOW
CVSS 2 - Authentication	NONE
CVSS 2 - Confidentiality Impact	COMPLETE
CVSS 2 - Availability Impact	COMPLETE
CVSS 2 - Base Score	7.2
Severity	HIGH
Exploitability Score	3.9
Impact Score	10.0
Obtain All Privilege	false
Obtain User Privilege	false
Obtain Other Privilege	false

Base Metric V3

No data provided.

Configurations

OR - Configuration 1

Cpe Version	Part	Vendor	Product	Version	Update	Edition	Language	SW Edition	Target SW	Target HW	Other	Version End Including
2.3	Application	Gnu	Bash	*	*	*	*	*	*	*	*	5.0
2.3	Application	Gnu	Bash	5.0	beta1	*	*	*	*	*	*
2.3	Application	Gnu	Bash	5.0	beta2	*	*	*	*	*	*
2.3	Application	Gnu	Bash	5.0	patch1	*	*	*	*	*	*
2.3	Application	Gnu	Bash	5.0	patch10	*	*	*	*	*	*
2.3	Application	Gnu	Bash	5.0	patch11	*	*	*	*	*	*
2.3	Application	Gnu	Bash	5.0	patch2	*	*	*	*	*	*
2.3	Application	Gnu	Bash	5.0	patch3	*	*	*	*	*	*
2.3	Application	Gnu	Bash	5.0	patch4	*	*	*	*	*	*
2.3	Application	Gnu	Bash	5.0	patch5	*	*	*	*	*	*
2.3	Application	Gnu	Bash	5.0	patch6	*	*	*	*	*	*
2.3	Application	Gnu	Bash	5.0	patch7	*	*	*	*	*	*
2.3	Application	Gnu	Bash	5.0	patch8	*	*	*	*	*	*
2.3	Application	Gnu	Bash	5.0	patch9	*	*	*	*	*	*
2.3	Application	Gnu	Bash	5.0	rc1	*	*	*	*	*	*

Vulnerable Software List

Vendor	Product	Versions
Gnu	Bash	*, 5.0

References

Name	Source	URL	Tags
http://packetstormsecurity.com/files/155498/Bash-5.0-Patch-11-Privilege-Escalation.html	http://packetstormsecurity.com/files/155498/Bash-5.0-Patch-11-Privilege-Escalation.html	MISC	Exploit Third Party Advisory VDB Entry
https://github.com/bminor/bash/commit/951bdaad7a18cc0dc1036bba86b18b90874d39ff	https://github.com/bminor/bash/commit/951bdaad7a18cc0dc1036bba86b18b90874d39ff	CONFIRM	Patch Third Party Advisory
https://security.netapp.com/advisory/ntap-20200430-0003/	https://security.netapp.com/advisory/ntap-20200430-0003/	CONFIRM
https://www.youtube.com/watch?v=-wGtxJ8opa8	https://www.youtube.com/watch?v=-wGtxJ8opa8	MISC	Exploit Third Party Advisory