OS Command Injection in openc3 (CVE-2026-77601)
Summary
OS command injection in openc3 (CVE-2026-77601). Successful exploitation can lead to full system takeover. Exploitable via POST /openc3-api/api. Mitigation: upgrade to 7.3.0 or later.
Original description
The description as published by the source.
Summary
An authenticated user can execute arbitrary operating system commands on the openc3-cosmos-cmd-tlm-api service. The pypi_url setting is interpolated, unescaped, into a command line that is run through a shell backtick when a plugin is installed. Shell metacharacters in the setting value are executed by /bin/sh.
Details
The pypi_url value is written through the set_setting API method, reachable over the JSON-RPC endpoint POST /openc3-api/api. In the open-source edition, authorize (openc3/lib/openc3/utilities/authorization.rb) verifies only that the session token is valid and returns the anonymous user; the permission: argument is not enforced, so any authenticated user can write the setting and install a plugin. In the Enterprise edition these actions require the admin role.
During plugin install, PluginModel.install_phase2 reads the setting and builds the argument string, then runs it through a backtick (openc3/lib/openc3/models/plugin_model.rb:288):
pypi_url = get_setting('pypi_url', scope: scope) # attacker-controlled, no validation
pypi_url += '/simple' if pypi_url
pip_args = "-i #{pypi_url} -r #{requirements_path}"
output = `/openc3/bin/pipinstall #{pip_args}` # Ruby backtick -> /bin/sh -c
get_setting appends /simple to the stored value, and a trailing # comments out that suffix and the remainder of the argument string. The python install branch runs whenever the installed plugin contains a `requirements.t…
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-77601 has been found in openc3.
Attackers can target a specific entry point like POST /openc3-api/api over the network to misuse the product.
Successful exploitation can lead to full system takeover. CVSS score: 8.8/10.
What to do: upgrade openc3 to 7.3.0 or later.
If unsure, ask your IT team or search "openc3 CVE-2026-77601" on the vendor's site.
CVE-2026-77601 (openc3) — CWE-78 / CVSS v3 8.8
Attack vector: remote (network-reachable) / no user interaction
Attack surface: POST /openc3-api/api / POST /openc3-api/auth/verify / POST /openc3-api/plugins / POST /openc3-api/plugins/install/
Patched: 7.3.0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
OS command injection (CWE-78) exists in openc3. Attackers reach the vulnerable code path via POST /openc3-api/api.
Check the vendor advisory for the affected versions of openc3. Attack surface: POST /openc3-api/api / POST /openc3-api/auth/verify / POST /openc3-api/plugins / POST /openc3-api/plugins/install/.
Severity: High (CVSS 8.8/10). Successful exploitation can lead to full system takeover.
Update to 7.3.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual POST /openc3-api/api requests with malformed payloads or SQL meta-characters. Run grep -r 'openc3' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'openc3' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
openc3を grep し、稼働しているサービス・バージョンを把握する。 -
2Hunt for indicators of compromise detect
grep 'POST /openc3-api/api' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'アクセスログで
POST /openc3-api/apiへの異常なリクエスト (不正な認証ヘッダ・SQLメタ文字)を過去 30〜90日分捜索。WAF/SIEM があれば該当パスのアラート発火履歴を確認。 -
3Apply patch patch
Upgrade openc3 to 7.3.0ステージング環境で 7.3.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスと、Step 2 で見つけた異常検知の続報チェックを含めること。
-
4Post-deployment verification verify
Replay attack against POST /openc3-api/api on staging to confirm patch closes the vectorパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番では Step 2 と同じログクエリでアラート再発が無いか継続監視。
Affected packages
References
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