CVE-2015-7837
kernel: securelevel disabled after kexec
Severity Score
5.5
*CVSS v3
Exploit Likelihood
*EPSS
Affected Versions
*CPE
Public Exploits
0
*Multiple Sources
Exploited in Wild
-
*KEV
Decision
-
*SSVC
Descriptions
The Linux kernel, as used in Red Hat Enterprise Linux 7, kernel-rt, and Enterprise MRG 2 and when booted with UEFI Secure Boot enabled, allows local users to bypass intended securelevel/secureboot restrictions by leveraging improper handling of secure_boot flag across kexec reboot.
El kernel de Linux, tal y como se emplea en Red Hat Enterprise Linux 7, kernel-rt y Enterprise MRG 2 y cuando se emplea con UEFI Secure Boot habilitado, permite que usuarios locales omitan las restricciones securelevel/secureboot previstas aprovechando la gestión incorrecta de la marca secure_boot cuando se reinicia kexec.
A flaw was found in the way the Linux kernel handled the securelevel functionality after performing a kexec operation. A local attacker could use this flaw to bypass the security mechanism of the securelevel/secureboot combination.
*Credits:
N/A
CVSS Scores
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability
Attack Vector
Attack Complexity
Authentication
Confidentiality
Integrity
Availability
Attack Vector
Attack Complexity
Authentication
Confidentiality
Integrity
Availability
* Common Vulnerability Scoring System
SSVC
- Decision:-
Exploitation
Automatable
Tech. Impact
* Organization's Worst-case Scenario
Timeline
- 2015-10-15 CVE Reserved
- 2015-11-20 CVE Published
- 2023-03-08 EPSS Updated
- 2024-08-06 CVE Updated
- ---------- Exploited in Wild
- ---------- KEV Due Date
- ---------- First Exploit
CWE
- CWE-254: 7PK - Security Features
- CWE-456: Missing Initialization of a Variable
CAPEC
References (7)
| URL | Tag | Source |
|---|---|---|
| http://www.openwall.com/lists/oss-security/2015/10/15/6 | Mailing List |
|
| http://www.securityfocus.com/bid/77097 | Third Party Advisory | |
| https://github.com/mjg59/linux/commit/4b2b64d5a6ebc84214755ebccd599baef7c1b798 | Issue Tracking |
| URL | Date | SRC |
|---|
| URL | Date | SRC |
|---|
| URL | Date | SRC |
|---|---|---|
| http://rhn.redhat.com/errata/RHSA-2015-2152.html | 2021-07-15 | |
| http://rhn.redhat.com/errata/RHSA-2015-2411.html | 2021-07-15 | |
| https://bugzilla.redhat.com/show_bug.cgi?id=1272472 | 2015-11-19 | |
| https://access.redhat.com/security/cve/CVE-2015-7837 | 2015-11-19 |
Affected Vendors, Products, and Versions
| Vendor | Product | Version | Other | Status | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Vendor | Product | Version | Other | Status | <-- --> | Vendor | Product | Version | Other | Status |
| Redhat Search vendor "Redhat" | Enterprise Linux Search vendor "Redhat" for product "Enterprise Linux" | 7.0 Search vendor "Redhat" for product "Enterprise Linux" and version "7.0" | - |
Affected
| ||||||
| Redhat Search vendor "Redhat" | Enterprise Linux Search vendor "Redhat" for product "Enterprise Linux" | 7.2 Search vendor "Redhat" for product "Enterprise Linux" and version "7.2" | - |
Affected
| ||||||
| Redhat Search vendor "Redhat" | Enterprise Linux Search vendor "Redhat" for product "Enterprise Linux" | 7.3 Search vendor "Redhat" for product "Enterprise Linux" and version "7.3" | - |
Affected
| ||||||
| Redhat Search vendor "Redhat" | Enterprise Linux Desktop Search vendor "Redhat" for product "Enterprise Linux Desktop" | 7.0 Search vendor "Redhat" for product "Enterprise Linux Desktop" and version "7.0" | - |
Affected
| ||||||
| Redhat Search vendor "Redhat" | Enterprise Linux Server Aus Search vendor "Redhat" for product "Enterprise Linux Server Aus" | 7.3 Search vendor "Redhat" for product "Enterprise Linux Server Aus" and version "7.3" | - |
Affected
| ||||||
| Redhat Search vendor "Redhat" | Enterprise Linux Server Aus Search vendor "Redhat" for product "Enterprise Linux Server Aus" | 7.4 Search vendor "Redhat" for product "Enterprise Linux Server Aus" and version "7.4" | - |
Affected
| ||||||
| Redhat Search vendor "Redhat" | Enterprise Linux Workstation Search vendor "Redhat" for product "Enterprise Linux Workstation" | 7.0 Search vendor "Redhat" for product "Enterprise Linux Workstation" and version "7.0" | - |
Affected
| ||||||
| Redhat Search vendor "Redhat" | Enterprise Mrg Search vendor "Redhat" for product "Enterprise Mrg" | 2.0 Search vendor "Redhat" for product "Enterprise Mrg" and version "2.0" | - |
Affected
| ||||||
| Redhat Search vendor "Redhat" | Kernel-rt Search vendor "Redhat" for product "Kernel-rt" | 7.0 Search vendor "Redhat" for product "Kernel-rt" and version "7.0" | - |
Affected
| ||||||