GHSA-76w9-p8mg-j927

Suggest an improvement
Source
https://github.com/advisories/GHSA-76w9-p8mg-j927
Import Source
https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2022/01/GHSA-76w9-p8mg-j927/GHSA-76w9-p8mg-j927.json
JSON Data
https://api.osv.dev/v1/vulns/GHSA-76w9-p8mg-j927
Aliases
Published
2022-01-06T22:07:14Z
Modified
2024-02-21T19:15:12Z
Severity
  • 6.7 (Medium) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
Summary
Out-of-bounds Write in nix
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 
{
    "nvd_published_at": "2021-12-27T00:15:00Z",
    "cwe_ids": [
        "CWE-787"
    ],
    "severity": "MODERATE",
    "github_reviewed": true,
    "github_reviewed_at": "2022-01-05T23:13:23Z"
}
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

Ecosystem specific 

{
    "affected_functions": [
        "nix::unistd::getgrouplist"
    ]
}

crates.io / nix

Package

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

Affected ranges

Type
SEMVER
Events
Introduced
0.21.0
Fixed
0.21.2

Ecosystem specific 

{
    "affected_functions": [
        "nix::unistd::getgrouplist"
    ]
}

crates.io / nix

Package

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

Affected ranges

Type
SEMVER
Events
Introduced
0.22.0
Fixed
0.22.2

Ecosystem specific 

{
    "affected_functions": [
        "nix::unistd::getgrouplist"
    ]
}