CVE-2019-18276
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (2.61%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 2.61% probability · 85th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-273
- Affected
- gnu/bash · netapp/hci management node · netapp/oncommand unified manager · netapp/solidfire · oracle/communications cloud native core policy
- Source
- cve@mitre.org
References
- http://packetstormsecurity.com/files/155498/Bash-5.0-Patch-11-Privilege-Escalation.htmlExploit, Third Party Advisory, VDB Entry
- https://github.com/bminor/bash/commit/951bdaad7a18cc0dc1036bba86b18b90874d39ffPatch, Third Party Advisory
- https://lists.apache.org/thread.html/rf9fa47ab66495c78bb4120b0754dd9531ca2ff0430f6685ac9b07772%40%3Cdev.mina.apache.org%3E
- https://security.gentoo.org/glsa/202105-34Third Party Advisory
- https://security.netapp.com/advisory/ntap-20200430-0003/Third Party Advisory
- https://www.oracle.com/security-alerts/cpuapr2022.htmlPatch, Third Party Advisory
- https://www.youtube.com/watch?v=-wGtxJ8opa8Exploit, Third Party Advisory
- http://packetstormsecurity.com/files/155498/Bash-5.0-Patch-11-Privilege-Escalation.htmlExploit, Third Party Advisory, VDB Entry
- https://github.com/bminor/bash/commit/951bdaad7a18cc0dc1036bba86b18b90874d39ffPatch, Third Party Advisory
- https://lists.apache.org/thread.html/rf9fa47ab66495c78bb4120b0754dd9531ca2ff0430f6685ac9b07772%40%3Cdev.mina.apache.org%3E
- https://security.gentoo.org/glsa/202105-34Third Party Advisory
- https://security.netapp.com/advisory/ntap-20200430-0003/Third Party Advisory
- https://www.oracle.com/security-alerts/cpuapr2022.htmlPatch, Third Party Advisory
- https://www.youtube.com/watch?v=-wGtxJ8opa8Exploit, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.