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PatchSiren cyber security CVE debrief

CVE-2017-5550 Linux CVE debrief

CVE-2017-5550 is a Linux kernel information-disclosure issue in pipe_advance that can expose uninitialized heap memory to a local user in limited, opportunistic circumstances. NVD lists affected kernels through 4.9.4 and notes the issue is fixed in Linux 4.9.5. The impact is confidentiality-only and requires local access, so the main concern is unintended data exposure on multi-user systems.

Vendor
Linux
Product
Unknown
CVSS
MEDIUM 5.5
CISA KEV
Not listed in stored evidence
Original CVE published
2017-02-06
Original CVE updated
2026-05-13
Advisory published
2017-02-06
Advisory updated
2026-05-13

Who should care

Linux kernel maintainers, distro security teams, and administrators of multi-user Linux systems running kernels older than 4.9.5. It matters most where untrusted or low-privilege local users can obtain shell access or run workloads on the same host.

Technical summary

The NVD description states there is an off-by-one error in pipe_advance in lib/iov_iter.c. Under the wrong buffer-release decision, reading from a pipe can return data from uninitialized heap-memory locations, allowing sensitive information disclosure to a local attacker. The CVSS vector provided by NVD is AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N, and the mapped weakness is CWE-200.

Defensive priority

Medium priority. Patch affected systems promptly, especially shared or multi-user Linux hosts, but this issue is lower urgency than remote code execution because it requires local privileges and affects confidentiality rather than integrity or availability.

Recommended defensive actions

  • Upgrade the Linux kernel to 4.9.5 or a vendor build that includes the fix.
  • Confirm whether your distribution has backported the fix to supported kernel packages, not just whether the version string is newer.
  • Prioritize remediation on servers, shared hosts, and systems where local users or workloads are not fully trusted.
  • Review local-access controls and reduce unnecessary shell or account access on affected systems.
  • Use the upstream commit and vendor release notes to verify that the patch is present in your deployed kernel build.
  • Update vulnerability inventories to mark kernels at or below 4.9.4 as affected unless the vendor explicitly documents a backport.

Evidence notes

This debrief is based on the supplied NVD record and linked official/vendor references only. The source record describes an off-by-one error in pipe_advance, a local information-disclosure impact, and affected versions through 4.9.4. NVD also supplies the CVSS 3.0 vector AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N and CWE-200. Linked references include the upstream kernel commit, Linux 4.9.5 changelog, oss-security patch discussion, and Red Hat bug tracker entry.

Sources and references

Verified primary and authoritative sources

  • CVE-2017-5550 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2017-5550

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2017-5550 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2017-5550

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental 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.