CVE intelligence and bounded remediation
CVE-2021-22926 — libcurl-using applications can ask for a specific client certificate to be used in a transfer
libcurl-using applications can ask for a specific client certificate to be used in a transfer. This is done with the `CURLOPT_SSLCERT` option (`--cert` with the command line tool).When libcurl is built to use the macOS native TLS library Secure Transport, an application can ask for the client certificate by name or with a file name - using the same option. If the name exists as a file, it will be used instead of by name.If the appliction runs with a current working directory that is writable by other users (like `/tmp`), a malicious user can create a file name with the same name as the app wants to use by name, and thereby trick the application to use the file based cert instead of the one referred to by name making libcurl send the wrong client certificate in the TLS connection handshake.
- Severity
- High
- CVSS
- 7.5 (3.1)
- Published
- 2021-08-05
- CISA KEV
- Not currently listed
- Ecosystem
- software/application
- Weaknesses
- CWE-840, CWE-295
Affected products
- haxx / curl
- netapp / active_iq_unified_manager
- netapp / clustered_data_ontap
- netapp / hci_management_node
- netapp / oncommand_insight
- netapp / oncommand_workflow_automation
Matched remediation archetype
Cryptography, certificate, signature, and channel validation
This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.
Check exposure
- Inventory affected algorithms, key uses, trust stores, certificate validation settings, random sources, and plaintext channels across clients and services.
- Determine which secrets, identities, signatures, or data protections depend on the affected primitive or validation path.
- Check debug, compatibility, fallback, and hostname or audience override settings in build and runtime configuration.
Remediate safely
- Use a maintained platform cryptographic API with approved algorithms, modes, parameters, randomness, and full peer identity validation.
- Remove insecure fallback and validation bypasses; separate keys by purpose and load them from managed secret storage.
- Plan rotation or reissuance for affected keys, certificates, tokens, hashes, or ciphertext and document compatibility sequencing.
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.