CVE-2016-7543 Fedoraproject CVE debrief

Who should care

Linux administrators, platform teams, and package maintainers who run GNU Bash on shared or multi-user systems should prioritize this issue, especially where untrusted local users may obtain shell access. Fedora, Red Hat, Gentoo, HPE, and other vendors referenced in the corpus may have issued downstream fixes or advisories for affected builds.

Technical summary

The vulnerability is a local command-execution flaw in Bash tied to environment-variable handling, specifically SHELLOPTS and PS4. In the NVD data, the CVSS v3.0 vector is AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H, indicating no prior privileges are required beyond local access, but successful abuse can result in full confidentiality, integrity, and availability impact if the shell runs with elevated privileges. The corpus lists GNU Bash through 4.3 as vulnerable and also associates Fedora 23, 24, and 25 package streams with the issue.

Defensive priority

High. The issue requires local access, so it is less urgent than a remotely exploitable flaw, but the root-level impact makes it important on any multi-user Linux environment or host where local logins, automation, or service accounts are present.

Recommended defensive actions

• Update Bash to a vendor-fixed release; the corpus indicates affected GNU Bash versions through 4.3 and downstream vendor advisories are available.
• Apply the relevant vendor errata or package updates referenced in the corpus for your distribution or appliance.
• Inventory systems for Bash versions and affected package streams, including Fedora 23/24/25 and any vendor-repackaged Bash builds.
• Prioritize multi-user servers, bastions, and systems where local shell access is possible.
• Verify remediation after patching by checking package versions against the vendor advisory for your platform.

Evidence notes

The CVE was published in the official NVD record on 2017-01-19. The supplied corpus includes a 2016-09-26 bug-bash mailing-list reference, multiple vendor advisories, and NVD CPE criteria marking GNU Bash through 4.3 as vulnerable. The weakness is listed as CWE-20, and the CVSS v3.0 vector is AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.