RUSTSEC-2021-0119

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Source

https://rustsec.org/advisories/RUSTSEC-2021-0119

Import Source

https://github.com/rustsec/advisory-db/blob/osv/crates/RUSTSEC-2021-0119.json

JSON Data

https://api.osv.dev/v1/vulns/RUSTSEC-2021-0119

Aliases

Published

2021-09-27T12:00:00Z

Modified

2023-11-08T04:07:23.055467Z

Summary

Out-of-bounds write in nix::unistd::getgrouplist

Details

On certain platforms, if a user has more than 16 groups, the nix::unistd::getgrouplist function will call the libc getgrouplist function with a length parameter greater than the size of the buffer it provides, resulting in an out-of-bounds write and memory corruption.

The libc getgrouplist function takes an in/out parameter ngroups specifying the size of the group buffer. When the buffer is too small to hold all of the requested user's group memberships, some libc implementations, including glibc and Solaris libc, will modify ngroups to indicate the actual number of groups for the user, in addition to returning an error. The version of nix::unistd::getgrouplist in nix 0.16.0 and up will resize the buffer to twice its size, but will not read or modify the ngroups variable. Thus, if the user has more than twice as many groups as the initial buffer size of 8, the next call to getgrouplist will then write past the end of the buffer.

The issue would require editing /etc/groups to exploit, which is usually only editable by the root user.

Database specific

{
    "license": "CC0-1.0"
}

References

Affected packages

crates.io / nix

Package

Name: nix; View open source insights on deps.dev
Purl: pkg:cargo/nix

Affected ranges

Type: SEMVER
Events: Introduced

0.16.0

Fixed

0.20.2

Introduced

0.21.0-0

Fixed

0.21.2

Introduced

0.22.0-0

Fixed

0.22.2

Introduced

0.23.0-0

Fixed

0.23.0

Ecosystem specific

{
    "affected_functions": null,
    "affects": {
        "os": [
            "linux",
            "freebsd",
            "android",
            "netbsd",
            "dragonfly",
            "openbsd",
            "fuchsia"
        ],
        "functions": [
            "nix::unistd::getgrouplist"
        ],
        "arch": []
    }
}

Database specific

{
    "cvss": null,
    "informational": null,
    "categories": [
        "memory-corruption"
    ]
}