CVE intelligence and bounded remediation

CVE-2018-12015 — Canonical Ubuntu Linux security vulnerability

High CVSS 7.5

In Perl through 5.26.2, the Archive::Tar module allows remote attackers to bypass a directory-traversal protection mechanism, and overwrite arbitrary files, via an archive file containing a symlink and a regular file with the same name.

Severity
High
CVSS
7.5 (3.0)
Published
2018-06-07
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-59

Affected products

  • canonical / ubuntu_linux / 12.04
  • canonical / ubuntu_linux / 14.04
  • canonical / ubuntu_linux / 16.04
  • canonical / ubuntu_linux / 17.10
  • canonical / ubuntu_linux / 18.04
  • debian / debian_linux / 8.0

Showing 6 representative product identities from 14 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Path traversal, unsafe upload, and file handling

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

Check exposure

  • Trace untrusted filenames, archive entries, URLs, and path segments into read, write, include, extraction, and upload operations.
  • Identify filesystem roots, mount permissions, symbolic-link behavior, archive handling, and whether uploaded content is web-accessible or executable.
  • Review canonicalization and containment checks across supported operating systems and storage backends.

Remediate safely

  • Generate server-side storage identifiers and resolve paths beneath a fixed root using filesystem-aware containment checks.
  • Reject absolute, parent-relative, alternate-separator, device, link, and archive entries that escape the intended root.
  • Store uploads outside executable or served paths, validate type and size, and use private atomic temporary files.

Authoritative sources

Complete CVE record and remediation plan

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