Debian LinuxOperating system · Debian

CVE-2019-17362

CRITICAL · 9.1 CVSS v3.1 Published 2019-10-09
Fix available
A fix is available. Upgrade to after 1.18.2 or later.
See remediation →
100/100
Remediation priority · Urgent
Public exploit Remotely reachable No privileges Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
In LibTomCrypt through 1.18.2, the der_decode_utf8_string function (in der_decode_utf8_string.c) does not properly detect certain invalid UTF-8 sequences. This allows context-dependent attackers to cause a denial of service (out-of-bounds read and crash) or read information from other memory locations via carefully crafted DER-encoded data.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-125

The code reads past the end (or before the start) of a buffer, returning memory that was never meant to be exposed. Attackers use it to leak secrets like keys or to defeat memory-protection defences. Remediation is validating indices and lengths before every read.

General guidance for the out-of-bounds read class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Debian LinuxOperating system
Affected:= 8.0
LibtomcryptApplication
Affected:<= 1.18.2

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to a release after 1.18.2
Vendor patch github.com →
Recommended fix Moderate confidence

Any LibTomCrypt release after 1.18.2 (the fix was merged via PR #508)

  1. Check your current LibTomCrypt version by examining your project's dependencies or running `grep -r "LTC_VERSION"` in the source
  2. If using Debian 8.0, note that the distribution is end-of-life and no longer receives security updates; consider upgrading to Debian 10 or 11
  3. For LibTomCrypt: Upgrade to the version containing the fix from PR #508 (a version after 1.18.2)
  4. If upgrading is not immediately possible, manually apply the fix from https://github.com/libtom/libtomcrypt/pull/508 by reviewing the changes to der_decode_utf8_string.c
  5. After upgrading or patching, rebuild any software that links against LibTomCrypt
  6. Test that DER-encoded UTF-8 string decoding works correctly with your application
Caveat Minimal risk; this is a security bugfix in input validation. Ensure your application handles invalid UTF-8 input gracefully after the fix.

Generated from the published advisory — verify against the referenced sources before acting.

We can identify the exact fixed release, upgrade, and verify it in staging — typical engagement from $3,550. Get the upgrade done

Scan for this in your stack

Free · runs locally
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2019-17362 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data