CVE intelligence and bounded remediation

CVE-2018-20819 — Dropbox Lepton security vulnerability

High CVSS 7.8

io/ZlibCompression.cc in the decompression component in Dropbox Lepton 1.2.1 allows attackers to cause a denial of service (heap-based buffer overflow and application crash) or possibly have unspecified other impact by crafting a jpg image file. The root cause is a missing check of header payloads that may be (incorrectly) larger than the maximum file size.

Severity
High
CVSS
7.8 (3.0)
Published
2019-04-23
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-787

Affected products

  • dropbox / lepton / 1.2.1

Matched remediation archetype

Buffer bounds, memory safety, and memory corruption

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Identify affected native-code versions, build flags, architectures, parsers, codecs, drivers, and input paths in all shipped artifacts.
  • Determine whether untrusted data reaches the affected routine and the process privilege, sandbox, and network exposure.
  • Confirm statically linked, vendored, firmware, and platform-provided copies, not only package-manager records.

Remediate safely

  • Apply the maintained upstream correction or replace the affected component, then rebuild every dependent artifact from clean inputs.
  • Adopt bounds-checked interfaces, validated sizes and integer conversions, clear ownership, and memory-safe components where practical.
  • Enable supported compiler and runtime hardening and add sanitized tests and fuzz regression seeds derived from non-weaponized fixtures.

Authoritative sources

Complete CVE record and remediation plan

The detailed catalog view below loads this exact record, its source evidence, and the full seven-phase agentic change plan.