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CVE-2017-6309 Debian CVE debrief

CVE-2017-6309 is a memory-corruption vulnerability in tnef before 1.4.13. NVD describes two type confusions in parse_file() that can lead to attacker-controlled invalid read and write operations. The official severity is High (CVSS 7.8), but exploitation requires local access and user interaction, so the main risk is to systems that process untrusted TNEF content or that ship affected tnef packages.

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

Security teams and administrators responsible for tnef deployments, mail gateways, desktop clients, or Linux distributions that package tnef should care most. The affected scope in NVD includes tnef versions through 1.4.12, and Debian Linux 8.0 is also listed in the affected CPE data.

Technical summary

NVD classifies the weakness as CWE-125 and CWE-787. The issue is in parse_file(), where two type confusions can cause invalid reads and writes under attacker influence. The CVSS vector is CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H, indicating local attack conditions with required user interaction and potentially severe impact on confidentiality, integrity, and availability.

Defensive priority

High priority for systems that parse untrusted TNEF data or still run tnef versions 1.4.12 or earlier; otherwise medium. The combination of memory corruption and user interaction makes patching important even though the attack surface is not remote by default.

Recommended defensive actions

  • Upgrade tnef to version 1.4.13 or later, or apply the upstream fix referenced in the project commit and change log.
  • Review package inventories for any software or distribution packages that include tnef, especially Linux systems using the affected CPEs.
  • Prefer blocking or sanitizing untrusted TNEF attachments at mail and content-processing boundaries until all affected systems are updated.
  • Validate vendor advisories and distro errata such as Debian DSA-3798 and Gentoo GLSA 201708-02 for package-specific remediation guidance.
  • If immediate upgrading is not possible, restrict which users and workflows can invoke tnef and reduce exposure to untrusted input.

Evidence notes

This debrief is based on the NVD record and the referenced vendor/advisory links supplied in the corpus. The vulnerability was published on 2017-02-24 and later modified on 2026-05-13 in the source record; those dates are used only for timing context. The core facts supported by the corpus are: affected tnef versions through 1.4.12, parse_file() type confusion, attacker-controlled invalid read/write behavior, and CVSS 7.8 with local access plus user interaction.

Sources and references

Verified primary and authoritative sources

  • CVE-2017-6309 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2017-6309

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

  • CVE-2017-6309 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2017-6309

    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.