Ecosyste.ms: Advisories

Security Advisories: GSA_kwCzR0hTQS13ajdmLTQ2OG0tNm12OM4AA3e_

Environment variables still accessible through /proc

Impact

Environment variables can be read from procfs unless a new process is started.

PoC

use birdcage::{Birdcage, Sandbox};
use std::{env, fs};

fn main() {
    Birdcage::new().lock().unwrap();

    assert_eq!(env::var_os("SECRET"), None);

    let environ = fs::read_to_string("/proc/self/environ").unwrap();
    assert!(!environ.contains("SECRET"), "ENVIRON CONTAINS SECRET:\n{environ}");
}

$  SECRET=test cargo run
thread 'main' panicked at src/main.rs:10:5:
ENVIRON CONTAINS SECRET:
 [truncated]

Possible Solutions

The simplest solution would be relying on the ptrace isolation and always spawning a new process by changing birdcage's API to create a new command. With an additional PID namespace the guarantees could be even further reinforced.

Permalink: https://github.com/advisories/GHSA-wj7f-468m-6mv8
JSON: https://advisories.ecosyste.ms/api/v1/advisories/GSA_kwCzR0hTQS13ajdmLTQ2OG0tNm12OM4AA3e_
Source: GitHub Advisory Database
Origin: Unspecified
Severity: Moderate
Classification: General
Published: 5 months ago
Updated: 5 months ago

CVSS Score: 4.0
CVSS vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Identifiers: GHSA-wj7f-468m-6mv8
References:

• https://github.com/phylum-dev/birdcage/security/advisories/GHSA-wj7f-468m-6mv8
• https://github.com/advisories/GHSA-wj7f-468m-6mv8

Repository: https://github.com/phylum-dev/birdcage
Blast Radius: 1.0

Affected Packages