CVE intelligence and bounded remediation

CVE-2021-22947 — Haxx Curl security vulnerability

Medium CVSS 5.9

When curl >= 7.20.0 and <= 7.78.0 connects to an IMAP or POP3 server to retrieve data using STARTTLS to upgrade to TLS security, the server can respond and send back multiple responses at once that curl caches. curl would then upgrade to TLS but not flush the in-queue of cached responses but instead continue using and trustingthe responses it got *before* the TLS handshake as if they were authenticated.Using this flaw, it allows a Man-In-The-Middle attacker to first inject the fake responses, then pass-through the TLS traffic from the legitimate server and trick curl into sending data back to the user thinking the attacker's injected data comes from the TLS-protected server.

Severity
Medium
CVSS
5.9 (3.1)
Published
2021-09-29
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-310, CWE-345

Affected products

  • haxx / curl
  • fedoraproject / fedora / 33
  • fedoraproject / fedora / 35
  • debian / debian_linux / 9.0
  • debian / debian_linux / 10.0
  • debian / debian_linux / 11.0

Showing 6 representative product identities from 38 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Supply-chain, dependency, build, and update integrity

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

Check exposure

  • Trace affected packages, source archives, build actions, plugins, installers, and updates from declared source to deployed artifact.
  • Confirm provenance, signatures or digests, namespace ownership, lockfile resolution, registry configuration, and build-runner trust boundaries.
  • Inventory direct, transitive, vendored, generated, and bundled copies across releases and distribution channels.

Remediate safely

  • Move to a maintained trusted artifact or remove the dependency; pin immutable identities and verify provenance and integrity before use.
  • Regenerate lockfiles and artifacts in a clean isolated build, minimize build credentials and network access, and produce an updated software bill of materials.
  • Require reviewed update policy, protected publishing, and reproducible or independently attestable builds where supported.

Authoritative sources

Complete CVE record and remediation plan

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