{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-104795", "assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "state": "PUBLISHED", "assignerShortName": "redhat", "dateReserved": "2026-10-02T13:07:13.820Z", "datePublished": "2026-10-14T10:55:17.144Z", "dateUpdated": "2026-10-14T15:26:53.109Z" }, "containers": { "cna": { "title": "Insights-runtime-extractor: insights-runtime-extractor: container escape via privileged binary execution", "metrics": [ { "other": { "content": { "value": "Important", "namespace": "https://access.redhat.com/security/updates/classification/" }, "type": "Red Hat severity rating" } }, { "cvssV3_1": { "attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 8.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "CHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H", "version": "3.1" }, "format": "CVSS" } ], "descriptions": [ { "lang": "en", "value": "The insights-runtime-extractor runs as a privileged DaemonSet (`hostPID: true`)\nthat scans container processes for runtime fingerprinting. When scanning a\ncontainer, the coordinator:\n\n1. **fork()s** a child process\n2. **setns()** into the target container's PID and mount namespaces\n3. **fchdir()** back to an orphaned FD pointing at the extractor's own root\n filesystem (where `/crio.sock` is hostPath-mounted)\n4. Calls **only `seteuid(target_uid)`** — changing the effective UID but leaving\n the **real UID and saved-set-UID at 0** and **retaining the permitted\n capability set**\n5. The `check_no_privileged_perms()` guard inspects only the Effective capability\n set (so it passes), and is **skipped entirely when the target runs as uid 0**\n6. The `VersionExecutable` fingerprint invokes `fpr_kind_executable` with\n `process.command_line[0]` — the target's argv[0], read from\n `/proc//cmdline` and **fully controlled by the workload**\n7. `fpr_kind_executable` calls `exec.Command(executable, \"--version\").Output()`\n — executing the **workload's own binary** inside the workload's mount\n namespace while **ruid=0 in the host user namespace**\n\nThe executed process can call `setuid(0)` to restore full root with\n`CAP_SYS_ADMIN`, and inherits the orphaned cwd which resolves into the extractor\ncontainer's filesystem containing the host CRI-O socket.\n\n## Affected Code\n\n### 1. Insufficient privilege drop (Rust — extractor coordinator)\n\n**File:** `extractor/src/insights_runtime_extractor.rs`\n\n```rust\n// Lines 139-146 — seteuid-only drop, guard skipped for root containers\njoin_process_namespaces(process.pid)?;\nchange_dir(current_dir);\nswitch_user(*process.uid)?;\nif *process.uid != 0 {\n perms::check_no_privileged_perms()\n .expect(\"Must not have privileged permissions to run fingerprints\");\n}\nfingerprint::run_fingerprints(&config, out_dir, &process);\n```\n\n```rust\n// Lines 182-185 — only effective UID changed; ruid/suid stay 0\nfn switch_user(uid: u32) -> Result<(), ScannerError> {\n debug!(\"... Becoming user: {uid}\");\n seteuid(uid.into()).map_err(|e| ScannerError::Errno(e))\n}\n```\n\n### 2. Execution of untrusted binary (Go — fingerprint)\n\n**File:** `fingerprints/pkg/utils/file.go`\n\n```go\n// Lines 75-80 — executes a path taken verbatim from workload's argv[0]\nfunc GetExecutableVersionOutput(executable string) (string, error) {\n out, err := exec.Command(executable, \"--version\").Output()\n if err != nil {\n return \"\", err\n }\n return string(out), nil\n}\n```\n\n### 3. Workload-controlled path forwarded (Rust — version_executable)\n\n**File:** `version_executable.rs`\n\n```rust\n// Lines 29-34 — workload-controlled command_line[0] forwarded to fingerprint\nreturn Some(vec![\n fpr_kind_executable,\n out_dir.to_string(),\n String::from(&process.command_line[0]),\n String::from(&version_executable.runtime_kind_name),\n]);\n```\n\n## Attack Pattern\n\n**Attacker:** Any tenant able to schedule a pod (unprivileged, any namespace)\n**Victim:** The node running the insights-runtime-extractor DaemonSet\n**Trigger:** Automatic — the DaemonSet scans all container processes on the node\n\n**Attack sequence:**\n\n1. Attacker creates a pod whose process name matches a configured\n versioned-executable pattern (`node`, `python`, `python3`, `MainThread`,\n or contains `java`)\n2. The pod's main binary (at the path matching argv[0]) is a malicious\n executable that calls `setuid(0)` to restore root\n3. When the insights operator triggers a scan, the DaemonSet forks, enters the\n attacker's mount namespace, and executes the attacker's binary with ruid=0\n4. The attacker's code regains full root with `CAP_SYS_ADMIN` in the host user\n namespace\n5. The inherited cwd contains the host CRI-O socket → full node compromise" } ], "affected": [ { "vendor": "Red Hat", "product": "Red Hat OpenShift Container Platform 4", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "openshift4/insights-runtime-extractor-rhel9", "defaultStatus": "affected", "cpes": [ "cpe:/a:redhat:openshift:4" ] } ], "references": [ { "url": "https://access.redhat.com/security/cve/CVE-2026-104795", "tags": [ "vdb-entry", "x_refsource_REDHAT" ] }, { "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2543917", "name": "RHBZ#2543917", "tags": [ "issue-tracking", "x_refsource_REDHAT" ] } ], "datePublic": "2026-10-14T09:47:53.272Z", "problemTypes": [ { "descriptions": [ { "cweId": "CWE-250", "description": "Execution with Unnecessary Privileges", "lang": "en", "type": "CWE" } ] } ], "x_redhatCweChain": "CWE-250: Execution with Unnecessary Privileges", "workarounds": [ { "lang": "en", "value": "The vulnerability requires a\ncode fix to implement a complete privilege drop (setting all three UID/GID\nfields, clearing all Linux capability sets, and setting `PR_SET_NO_NEW_PRIVS`)\nbefore executing any fingerprint binary." } ], "timeline": [ { "lang": "en", "time": "2026-09-30T12:50:08.063Z", "value": "Reported to Red Hat." }, { "lang": "en", "time": "2026-10-14T09:47:53.272Z", "value": "Made public." } ], "providerMetadata": { "orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "shortName": "redhat", "dateUpdated": "2026-10-14T10:55:17.144Z" }, "x_generator": { "engine": "cvelib 1.8.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "timestamp": "2026-10-14T15:25:50.103511Z", "id": "CVE-2026-104795", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "role": "CISA Coordinator", "version": "2.0.3" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-14T15:26:53.109Z" } } ] } }