// For flags

CVE-2024-45310

runc can be confused to create empty files/directories on the host

Severity Score

3.6
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track
*SSVC
Descriptions

runc is a CLI tool for spawning and running containers according to the OCI specification. runc 1.1.13 and earlier, as well as 1.2.0-rc2 and earlier, can be tricked into creating empty files or directories in arbitrary locations in the host filesystem by sharing a volume between two containers and exploiting a race with `os.MkdirAll`. While this could be used to create empty files, existing files would not be truncated. An attacker must have the ability to start containers using some kind of custom volume configuration. Containers using user namespaces are still affected, but the scope of places an attacker can create inodes can be significantly reduced. Sufficiently strict LSM policies (SELinux/Apparmor) can also in principle block this attack -- we suspect the industry standard SELinux policy may restrict this attack's scope but the exact scope of protection hasn't been analysed. This is exploitable using runc directly as well as through Docker and Kubernetes. The issue is fixed in runc v1.1.14 and v1.2.0-rc3.

Some workarounds are available. Using user namespaces restricts this attack fairly significantly such that the attacker can only create inodes in directories that the remapped root user/group has write access to. Unless the root user is remapped to an actual
user on the host (such as with rootless containers that don't use `/etc/sub[ug]id`), this in practice means that an attacker would only be able to create inodes in world-writable directories. A strict enough SELinux or AppArmor policy could in principle also restrict the scope if a specific label is applied to the runc runtime, though neither the extent to which the standard existing policies block this attack nor what exact policies are needed to sufficiently restrict this attack have been thoroughly tested.

*Credits: N/A
CVSS Scores
Attack Vector
Local
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Changed
Confidentiality
None
Integrity
Low
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2024-08-26 CVE Reserved
  • 2024-09-03 CVE Published
  • 2024-09-03 CVE Updated
  • 2024-09-04 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-61: UNIX Symbolic Link (Symlink) Following
  • CWE-363: Race Condition Enabling Link Following
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Opencontainers
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Runc
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< 1.1.14
Search vendor "Opencontainers" for product "Runc" and version " < 1.1.14"
en
Affected
Opencontainers
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Runc
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1.2.0
Search vendor "Opencontainers" for product "Runc" and version "1.2.0"
en
Affected