CVE intelligence and bounded remediation

CVE-2010-20049 — LeapFTP < 3.1.x contains a stack-based buffer overflow vulnerability in its FTP client parser

Critical CVSS 9.3

LeapFTP < 3.1.x contains a stack-based buffer overflow vulnerability in its FTP client parser. When the client receives a directory listing containing a filename longer than 528 bytes, the application fails to properly bound-check the input and overwrites the Structured Exception Handler (SEH) chain. This allows an attacker operating a malicious FTP server to execute arbitrary code on the victim’s machine when the file is listed or downloaded.

Severity
Critical
CVSS
9.3 (4.0)
Published
2025-08-20
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-121

Affected products

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Matched remediation archetype

Buffer bounds, memory safety, and memory corruption

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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

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