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CVE-2017-6307 Debian CVE debrief

CVE-2017-6307 is a high-severity memory corruption issue in tnef before 1.4.13. NVD describes two out-of-bounds writes in src/mapi_attr.c:mapi_attr_read(), with attacker-controlled input potentially leading to invalid read and write operations. The available references indicate that upstream and downstream maintainers issued fixes and advisories, so the main defensive priority is to identify affected versions and apply the patched release or vendor backport as soon as possible.

Vendor
Debian
Product
CVE-2017-6307
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 maintainers running tnef or packages that embed it, especially mail gateways, attachment-processing systems, and Linux distributions that ship tnef. Security teams should also care if user-supplied TNEF data is processed automatically.

Technical summary

NVD assigns CWE-787 (out-of-bounds write) and a CVSS 3.0 vector of AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. The issue is in mapi_attr_read() within src/mapi_attr.c, where malformed attacker-controlled input can drive out-of-bounds memory access. The affected upstream range is listed as tnef through 1.4.12, with 1.4.13 or later indicated by the supplied description and references as the fixed release line.

Defensive priority

High for environments that parse untrusted TNEF content, but not an emergency for systems that never handle such data. Because exploitation requires user interaction and local conditions, prioritize patching exposed mail and file-processing workflows first.

Recommended defensive actions

  • Upgrade tnef to 1.4.13 or later, or apply the relevant vendor backport if you use a distribution package.
  • Inventory systems and applications that call tnef or process TNEF attachments automatically.
  • Treat untrusted TNEF data as unsafe until patched; reduce or disable automatic processing where feasible.
  • Verify distribution advisories and package changelogs for your platform, since downstream fixes may differ from upstream versioning.
  • After remediation, confirm the installed package version and document the patch status for affected hosts.

Evidence notes

Supported by the NVD CVE record, which lists the vulnerability as an out-of-bounds write in src/mapi_attr.c:mapi_attr_read() and assigns CWE-787. The supplied references also include Debian, Gentoo, and X41 advisories plus the upstream commit and ChangeLog, indicating a public fix path. The NVD CPE criteria identify the affected upstream product as tnef up to 1.4.12.

Official resources

Published by NVD on 2017-02-24 and later modified on 2026-05-13. The supplied reference set points to upstream patch material and downstream advisories; this debrief avoids exploit details and relies only on the provided corpus and official