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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
Unknown
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.