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

PublishedNovember 28, 2019
Last ModifiedApril 30, 2020
Assignercve@mitre.org
Data TypeCVE
Data FormatMITRE
Data Version4.0
Problem TypeCWE-273
CVE Data Version4.0

Base Metric V2

CVSS 2 - Version2.0
CVSS 2 - Vector StringAV:L/AC:L/Au:N/C:C/I:C/A:C
CVSS 2 - Access VectorLOCAL
CVSS 2 - Access ComplexityLOW
CVSS 2 - AuthenticationNONE
CVSS 2 - Confidentiality ImpactCOMPLETE
CVSS 2 - Availability ImpactCOMPLETE
CVSS 2 - Base Score7.2
SeverityHIGH
Exploitability Score3.9
Impact Score10.0
Obtain All Privilegefalse
Obtain User Privilegefalse
Obtain Other Privilegefalse

Base Metric V3

No data provided.

Configurations

  • OR - Configuration 1
    Cpe VersionPartVendorProductVersionUpdateEditionLanguageSW EditionTarget SWTarget HWOtherVersion Start IncludingVersion End IncludingVersion Start ExcludingVersion End Excluding
    2.3ApplicationGnuBash********5.0
    2.3ApplicationGnuBash5.0beta1******
    2.3ApplicationGnuBash5.0beta2******
    2.3ApplicationGnuBash5.0patch1******
    2.3ApplicationGnuBash5.0patch10******
    2.3ApplicationGnuBash5.0patch11******
    2.3ApplicationGnuBash5.0patch2******
    2.3ApplicationGnuBash5.0patch3******
    2.3ApplicationGnuBash5.0patch4******
    2.3ApplicationGnuBash5.0patch5******
    2.3ApplicationGnuBash5.0patch6******
    2.3ApplicationGnuBash5.0patch7******
    2.3ApplicationGnuBash5.0patch8******
    2.3ApplicationGnuBash5.0patch9******
    2.3ApplicationGnuBash5.0rc1******

Vulnerable Software List

VendorProductVersions
Gnu Bash *, 5.0

References

NameSourceURLTags
http://packetstormsecurity.com/files/155498/Bash-5.0-Patch-11-Privilege-Escalation.htmlhttp://packetstormsecurity.com/files/155498/Bash-5.0-Patch-11-Privilege-Escalation.htmlMISCExploit Third Party Advisory VDB Entry
https://github.com/bminor/bash/commit/951bdaad7a18cc0dc1036bba86b18b90874d39ffhttps://github.com/bminor/bash/commit/951bdaad7a18cc0dc1036bba86b18b90874d39ffCONFIRMPatch 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=-wGtxJ8opa8https://www.youtube.com/watch?v=-wGtxJ8opa8MISCExploit Third Party Advisory