CVE-2023-6660 NFS client data corruption and kernel memory disclosure

2023-12-1308:23:40

freebsd

www.cve.org

nfs client

data corruption

kernel memory

sensitive information

unprivileged user

network transmission

mbufs

inter-process communication

system applications

nfs mount

corrupted data

snooping

network hosts

6.6 Medium

AI Score

Confidence

High

0.0005 Low

EPSS

Percentile

18.3%

JSON

When a program running on an affected system appends data to a file via an NFS client mount, the bug can cause the NFS client to fail to copy in the data to be written but proceed as though the copy operation had succeeded. This means that the data to be written is instead replaced with whatever data had been in the packet buffer previously. Thus, an unprivileged user with access to an affected system may abuse the bug to trigger disclosure of sensitive information. In particular, the leak is limited to data previously stored in mbufs, which are used for network transmission and reception, and for certain types of inter-process communication.

The bug can also be triggered unintentionally by system applications, in which case the data written by the application to an NFS mount may be corrupted. Corrupted data is written over the network to the NFS server, and thus also susceptible to being snooped by other hosts on the network.

Note that the bug exists only in the NFS client; the version and implementation of the server has no effect on whether a given system is affected by the problem.

CNA Affected

[
  {
    "defaultStatus": "unknown",
    "modules": [
      "nfsclient"
    ],
    "product": "FreeBSD",
    "vendor": "FreeBSD",
    "versions": [
      {
        "lessThan": "p3",
        "status": "affected",
        "version": "14.0-RELEASE",
        "versionType": "release"
      },
      {
        "lessThan": "p8",
        "status": "affected",
        "version": "13.2-RELEASE",
        "versionType": "release"
      }
    ]
  }
]