ID CVE-2021-43784
Summary runc is a CLI tool for spawning and running containers on Linux according to the OCI specification. In runc, netlink is used internally as a serialization system for specifying the relevant container configuration to the `C` portion of the code (responsible for the based namespace setup of containers). In all versions of runc prior to 1.0.3, the encoder did not handle the possibility of an integer overflow in the 16-bit length field for the byte array attribute type, meaning that a large enough malicious byte array attribute could result in the length overflowing and the attribute contents being parsed as netlink messages for container configuration. This vulnerability requires the attacker to have some control over the configuration of the container and would allow the attacker to bypass the namespace restrictions of the container by simply adding their own netlink payload which disables all namespaces. The main users impacted are those who allow untrusted images with untrusted configurations to run on their machines (such as with shared cloud infrastructure). runc version 1.0.3 contains a fix for this bug. As a workaround, one may try disallowing untrusted namespace paths from your container. It should be noted that untrusted namespace paths would allow the attacker to disable namespace protections entirely even in the absence of this bug.
References
Vulnerable Configurations
  • cpe:2.3:a:linuxfoundation:runc:-:*:*:*:*:*:*:*
    cpe:2.3:a:linuxfoundation:runc:-:*:*:*:*:*:*:*
  • cpe:2.3:a:linuxfoundation:runc:0.0.1:*:*:*:*:*:*:*
    cpe:2.3:a:linuxfoundation:runc:0.0.1:*:*:*:*:*:*:*
  • cpe:2.3:a:linuxfoundation:runc:0.0.2:*:*:*:*:*:*:*
    cpe:2.3:a:linuxfoundation:runc:0.0.2:*:*:*:*:*:*:*
  • cpe:2.3:a:linuxfoundation:runc:0.0.2.1:*:*:*:*:*:*:*
    cpe:2.3:a:linuxfoundation:runc:0.0.2.1:*:*:*:*:*:*:*
  • cpe:2.3:a:linuxfoundation:runc:0.0.3:*:*:*:*:*:*:*
    cpe:2.3:a:linuxfoundation:runc:0.0.3:*:*:*:*:*:*:*
  • cpe:2.3:a:linuxfoundation:runc:0.0.4:*:*:*:*:*:*:*
    cpe:2.3:a:linuxfoundation:runc:0.0.4:*:*:*:*:*:*:*
  • cpe:2.3:a:linuxfoundation:runc:0.0.5:*:*:*:*:*:*:*
    cpe:2.3:a:linuxfoundation:runc:0.0.5:*:*:*:*:*:*:*
  • cpe:2.3:a:linuxfoundation:runc:0.0.6:*:*:*:*:*:*:*
    cpe:2.3:a:linuxfoundation:runc:0.0.6:*:*:*:*:*:*:*
  • cpe:2.3:a:linuxfoundation:runc:0.0.7:*:*:*:*:*:*:*
    cpe:2.3:a:linuxfoundation:runc:0.0.7:*:*:*:*:*:*:*
  • cpe:2.3:a:linuxfoundation:runc:0.0.8:*:*:*:*:*:*:*
    cpe:2.3:a:linuxfoundation:runc:0.0.8:*:*:*:*:*:*:*
  • cpe:2.3:a:linuxfoundation:runc:0.0.9:*:*:*:*:*:*:*
    cpe:2.3:a:linuxfoundation:runc:0.0.9:*:*:*:*:*:*:*
  • cpe:2.3:a:linuxfoundation:runc:0.1.0:*:*:*:*:*:*:*
    cpe:2.3:a:linuxfoundation:runc:0.1.0:*:*:*:*:*:*:*
  • cpe:2.3:a:linuxfoundation:runc:0.1.1:*:*:*:*:*:*:*
    cpe:2.3:a:linuxfoundation:runc:0.1.1:*:*:*:*:*:*:*
  • cpe:2.3:a:linuxfoundation:runc:1.0.0:rc1:*:*:*:*:*:*
    cpe:2.3:a:linuxfoundation:runc:1.0.0:rc1:*:*:*:*:*:*
  • cpe:2.3:a:linuxfoundation:runc:1.0.0:rc10:*:*:*:*:*:*
    cpe:2.3:a:linuxfoundation:runc:1.0.0:rc10:*:*:*:*:*:*
  • cpe:2.3:a:linuxfoundation:runc:1.0.0:rc2:*:*:*:*:*:*
    cpe:2.3:a:linuxfoundation:runc:1.0.0:rc2:*:*:*:*:*:*
  • cpe:2.3:a:linuxfoundation:runc:1.0.0:rc3:*:*:*:*:*:*
    cpe:2.3:a:linuxfoundation:runc:1.0.0:rc3:*:*:*:*:*:*
  • cpe:2.3:a:linuxfoundation:runc:1.0.0:rc4:*:*:*:*:*:*
    cpe:2.3:a:linuxfoundation:runc:1.0.0:rc4:*:*:*:*:*:*
  • cpe:2.3:a:linuxfoundation:runc:1.0.0:rc5:*:*:*:*:*:*
    cpe:2.3:a:linuxfoundation:runc:1.0.0:rc5:*:*:*:*:*:*
  • cpe:2.3:a:linuxfoundation:runc:1.0.0:rc6:*:*:*:*:*:*
    cpe:2.3:a:linuxfoundation:runc:1.0.0:rc6:*:*:*:*:*:*
  • cpe:2.3:a:linuxfoundation:runc:1.0.0:rc7:*:*:*:*:*:*
    cpe:2.3:a:linuxfoundation:runc:1.0.0:rc7:*:*:*:*:*:*
  • cpe:2.3:a:linuxfoundation:runc:1.0.0:rc8:*:*:*:*:*:*
    cpe:2.3:a:linuxfoundation:runc:1.0.0:rc8:*:*:*:*:*:*
  • cpe:2.3:a:linuxfoundation:runc:1.0.0:rc9:*:*:*:*:*:*
    cpe:2.3:a:linuxfoundation:runc:1.0.0:rc9:*:*:*:*:*:*
  • cpe:2.3:a:linuxfoundation:runc:1.0.0:rc90:*:*:*:*:*:*
    cpe:2.3:a:linuxfoundation:runc:1.0.0:rc90:*:*:*:*:*:*
  • cpe:2.3:a:linuxfoundation:runc:1.0.0:rc91:*:*:*:*:*:*
    cpe:2.3:a:linuxfoundation:runc:1.0.0:rc91:*:*:*:*:*:*
  • cpe:2.3:a:linuxfoundation:runc:1.0.0:rc92:*:*:*:*:*:*
    cpe:2.3:a:linuxfoundation:runc:1.0.0:rc92:*:*:*:*:*:*
  • cpe:2.3:a:linuxfoundation:runc:1.0.0:rc93:*:*:*:*:*:*
    cpe:2.3:a:linuxfoundation:runc:1.0.0:rc93:*:*:*:*:*:*
  • cpe:2.3:a:linuxfoundation:runc:1.0.0:rc94:*:*:*:*:*:*
    cpe:2.3:a:linuxfoundation:runc:1.0.0:rc94:*:*:*:*:*:*
  • cpe:2.3:a:linuxfoundation:runc:1.0.0:rc95:*:*:*:*:*:*
    cpe:2.3:a:linuxfoundation:runc:1.0.0:rc95:*:*:*:*:*:*
  • cpe:2.3:a:linuxfoundation:runc:1.0.1:*:*:*:*:*:*:*
    cpe:2.3:a:linuxfoundation:runc:1.0.1:*:*:*:*:*:*:*
  • cpe:2.3:a:linuxfoundation:runc:1.0.2:*:*:*:*:*:*:*
    cpe:2.3:a:linuxfoundation:runc:1.0.2:*:*:*:*:*:*:*
  • cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
    cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
CVSS
Base: 6.0 (as of 08-12-2021 - 18:05)
Impact:
Exploitability:
CWE CWE-190
CAPEC
  • Forced Integer Overflow
    This attack forces an integer variable to go out of range. The integer variable is often used as an offset such as size of memory allocation or similarly. The attacker would typically control the value of such variable and try to get it out of range. For instance the integer in question is incremented past the maximum possible value, it may wrap to become a very small, or negative number, therefore providing a very incorrect value which can lead to unexpected behavior. At worst the attacker can execute arbitrary code.
Access
VectorComplexityAuthentication
NETWORK MEDIUM SINGLE
Impact
ConfidentialityIntegrityAvailability
PARTIAL PARTIAL PARTIAL
cvss-vector via4 AV:N/AC:M/Au:S/C:P/I:P/A:P
Last major update 08-12-2021 - 18:05
Published 06-12-2021 - 18:15
Last modified 08-12-2021 - 18:05
Back to Top