CVE-2018-18397
kernel: userfaultfd bypasses tmpfs file permissions
Severity Score
5.5
*CVSS v3
Exploit Likelihood
*EPSS
Affected Versions
*CPE
Public Exploits
1
*Multiple Sources
Exploited in Wild
-
*KEV
Decision
-
*SSVC
Descriptions
The userfaultfd implementation in the Linux kernel before 4.19.7 mishandles access control for certain UFFDIO_ ioctl calls, as demonstrated by allowing local users to write data into holes in a tmpfs file (if the user has read-only access to that file, and that file contains holes), related to fs/userfaultfd.c and mm/userfaultfd.c.
La implementación de userfaultfd en el kernel de Linux en versiones anteriores a la 4.17 gestiona de manera incorrecta para ciertas llamadas ioctl UFFDIO_, tal y como queda demostrado al permitir que usuarios locales escriban datos en huecos en un archivo tmpfs (si el usuario tiene acceso de solo lectura a dicho archivo que contiene huecos). Esto está relacionado con fs/userfaultfd.c y mm/userfaultfd.c.
A flaw was found in the Linux kernel with files on tmpfs and hugetlbfs. An attacker is able to bypass file permissions on filesystems mounted with tmpfs/hugetlbs to modify a file and possibly disrupt normal system behavior. At this time there is an understanding there is no crash or privilege escalation but the impact of modifications on these filesystems of files in production systems may have adverse affects.
Linux userfaultfd bypasses tmpfs file permissions.
*Credits:
N/A
CVSS Scores
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
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
- 2018-10-16 CVE Reserved
- 2018-12-12 CVE Published
- 2023-03-08 EPSS Updated
- 2024-08-05 CVE Updated
- 2024-08-05 First Exploit
- ---------- Exploited in Wild
- ---------- KEV Due Date
CWE
- CWE-20: Improper Input Validation
- CWE-863: Incorrect Authorization
CAPEC
References (16)
| URL | Tag | Source |
|---|
| URL | Date | SRC |
|---|---|---|
| https://bugs.chromium.org/p/project-zero/issues/detail?id=1700 | 2024-08-05 |
| URL | Date | SRC |
|---|---|---|
| https://access.redhat.com/errata/RHBA-2019:0327 | 2020-08-24 | |
| https://access.redhat.com/errata/RHSA-2019:0163 | 2020-08-24 | |
| https://access.redhat.com/errata/RHSA-2019:0202 | 2020-08-24 | |
| https://access.redhat.com/errata/RHSA-2019:0324 | 2020-08-24 | |
| https://access.redhat.com/errata/RHSA-2019:0831 | 2020-08-24 | |
| https://usn.ubuntu.com/3901-1 | 2020-08-24 | |
| https://usn.ubuntu.com/3901-2 | 2020-08-24 | |
| https://usn.ubuntu.com/3903-1 | 2020-08-24 | |
| https://usn.ubuntu.com/3903-2 | 2020-08-24 | |
| https://access.redhat.com/security/cve/CVE-2018-18397 | 2019-04-23 | |
| https://bugzilla.redhat.com/show_bug.cgi?id=1641548 | 2019-04-23 |
Affected Vendors, Products, and Versions
| Vendor | Product | Version | Other | Status | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Vendor | Product | Version | Other | Status | <-- --> | Vendor | Product | Version | Other | Status |
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | < 4.19.7 Search vendor "Linux" for product "Linux Kernel" and version " < 4.19.7" | - |
Affected
| ||||||
| Redhat Search vendor "Redhat" | Openshift Container Platform Search vendor "Redhat" for product "Openshift Container Platform" | 3.11 Search vendor "Redhat" for product "Openshift Container Platform" and version "3.11" | - |
Affected
| ||||||
| Redhat Search vendor "Redhat" | Virtualization Host Search vendor "Redhat" for product "Virtualization Host" | 4.0 Search vendor "Redhat" for product "Virtualization Host" and version "4.0" | - |
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 Search vendor "Redhat" for product "Enterprise Linux Server" | 7.0 Search vendor "Redhat" for product "Enterprise Linux Server" and version "7.0" | - |
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 Server Aus Search vendor "Redhat" for product "Enterprise Linux Server Aus" | 7.6 Search vendor "Redhat" for product "Enterprise Linux Server Aus" and version "7.6" | - |
Affected
| ||||||
| Redhat Search vendor "Redhat" | Enterprise Linux Server Eus Search vendor "Redhat" for product "Enterprise Linux Server Eus" | 7.4 Search vendor "Redhat" for product "Enterprise Linux Server Eus" and version "7.4" | - |
Affected
| ||||||
| Redhat Search vendor "Redhat" | Enterprise Linux Server Eus Search vendor "Redhat" for product "Enterprise Linux Server Eus" | 7.5 Search vendor "Redhat" for product "Enterprise Linux Server Eus" and version "7.5" | - |
Affected
| ||||||
| Redhat Search vendor "Redhat" | Enterprise Linux Server Eus Search vendor "Redhat" for product "Enterprise Linux Server Eus" | 7.6 Search vendor "Redhat" for product "Enterprise Linux Server Eus" and version "7.6" | - |
Affected
| ||||||
| Redhat Search vendor "Redhat" | Enterprise Linux Server Tus Search vendor "Redhat" for product "Enterprise Linux Server Tus" | 7.4 Search vendor "Redhat" for product "Enterprise Linux Server Tus" and version "7.4" | - |
Affected
| ||||||
| Redhat Search vendor "Redhat" | Enterprise Linux Server Tus Search vendor "Redhat" for product "Enterprise Linux Server Tus" | 7.6 Search vendor "Redhat" for product "Enterprise Linux Server Tus" and version "7.6" | - |
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
| ||||||
| Canonical Search vendor "Canonical" | Ubuntu Linux Search vendor "Canonical" for product "Ubuntu Linux" | 14.04 Search vendor "Canonical" for product "Ubuntu Linux" and version "14.04" | lts |
Affected
| ||||||
| Canonical Search vendor "Canonical" | Ubuntu Linux Search vendor "Canonical" for product "Ubuntu Linux" | 16.04 Search vendor "Canonical" for product "Ubuntu Linux" and version "16.04" | lts |
Affected
| ||||||
| Canonical Search vendor "Canonical" | Ubuntu Linux Search vendor "Canonical" for product "Ubuntu Linux" | 18.04 Search vendor "Canonical" for product "Ubuntu Linux" and version "18.04" | lts |
Affected
| ||||||
| Canonical Search vendor "Canonical" | Ubuntu Linux Search vendor "Canonical" for product "Ubuntu Linux" | 18.10 Search vendor "Canonical" for product "Ubuntu Linux" and version "18.10" | - |
Affected
| ||||||