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CVE-2017-6303 Debian CVE debrief

CVE-2017-6303 is a high-severity memory-corruption issue in ytnef. NVD describes it as an invalid write and integer overflow in versions before 1.9.1, with affected CPEs for ytnef through 1.9 and Debian 8.0/9.0 packages. Because the attack surface includes user interaction and can impact confidentiality, integrity, and availability, systems that process TNEF content through ytnef should be prioritized for remediation.

Vendor
Debian
Product
CVE-2017-6303
CVSS
HIGH 7.8
CISA KEV
Not listed in stored evidence
Original CVE published
2017-02-24
Original CVE updated
2026-05-13
Advisory published
2017-02-24
Advisory updated
2026-05-13

Who should care

Administrators and developers running ytnef directly, and teams relying on downstream packages such as Debian 8/9 builds that include ytnef. Security teams should also review any software that delegates TNEF parsing to ytnef.

Technical summary

The NVD record maps the issue to CWE-190 (integer overflow) and a CVSS 3.0 vector of AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. The vulnerability is described as an invalid write and integer overflow in ytnef before 1.9.1. The record also links the issue to a vendor advisory, an upstream patch pull request, and a third-party advisory, indicating a coordinated fix path across upstream and downstream packaging.

Defensive priority

High. The CVSS score is 7.8 and the weakness class includes memory-safety impact with potential for serious compromise once triggered. Even though user interaction is required, affected parsers are often exposed to untrusted content, making timely patching important.

Recommended defensive actions

  • Upgrade ytnef to version 1.9.1 or later, or apply the vendor/backported fix provided by your Linux distribution.
  • Verify whether any Debian 8.0 or 9.0 systems still ship a vulnerable ytnef package and remediate them first.
  • Inventory applications and services that process TNEF content and confirm whether they call ytnef directly or via a bundled dependency.
  • Treat untrusted TNEF inputs as risky until patched; limit exposure of affected systems to unnecessary file-processing workflows.
  • Track the referenced Debian advisory, upstream patch PR, and X41 advisory for packaging or backport guidance.

Evidence notes

Primary evidence comes from the NVD record for CVE-2017-6303, which states the issue is in ytnef before 1.9.1 and classifies it as CWE-190. The NVD metadata lists vulnerable CPEs for ytnef through 1.9 and Debian 8.0/9.0, and references Debian DSA-3846, an upstream GitHub pull request (#27), and an X41 advisory. CVE publishedAt is 2017-02-24T04:59:00.437Z; modifiedAt is 2026-05-13T00:24:29.033Z.

Official resources

Publicly disclosed in the CVE record on 2017-02-24. NVD last modified the record on 2026-05-13.