Symfony Vulnerable to Identity Spoofing via Unanchored DN Regex in X509Authenticator
### Description `X509Authenticator` implements client-certificate (mTLS) authentication: the web server validates the client's certificate against a trusted CA, then passes the certificate's Subject DN (Distinguished Name: a string like `CN=Alice,O=Example,emailAddress=alice@example.com`) to Symfony via `$_SERVER['SSL_CLIENT_S_DN']`. Symfony extrac...
CVSS 7.5 LOW. SENTINEL APEX recommends immediate patch evaluation. Intelligence from 1 confirmed source(s).
📋 Executive Summary
CYBERDUDEBIVASH SENTINEL APEX has confirmed a LOW-tier threat intelligence signal for CVE-2026-45063 affecting composer symfony/security-http. Composite threat score: 44/100. Intelligence corroborated across 1 source(s): github_advisories. CVSS base score: 7.5. Exploitation probability assessed as HIGH based on vulnerability characteristics.
⚠️ Business Impact Analysis
- ⚠️ composer symfony/security-http users face material security risk requiring immediate remediation
🔗 Attack Chain Analysis
Step-by-step attack chain based on observed TTPs and vulnerability characteristics:
| # | Phase | Attacker Action | MITRE |
|---|---|---|---|
1 |
Reconnaissance | Attacker identifies exposed symfony/security-http instances via Shodan, Censys, or targeted scanning | TA0043 |
2 |
Initial Access | Spear-phishing with malicious attachment or link targeting ${item.vendor} users | T1566 |
3 |
Persistence | Backdoor, scheduled task, or new admin account created for persistent access | T1053 |
4 |
Command & Control | Attacker establishes persistent C2 channel using HTTPS or DNS tunneling | T1071 |
5 |
Impact / Objectives | Intellectual property theft, espionage, cryptomining, or preparation for future attack stage | T1657 |
⚠ Deep Dive Analysis
This high-severity vulnerability in composer symfony/security-http (CVSS 7.5) represents a significant attack surface. SENTINEL APEX assesses exploitation to be technically feasible with moderate effort. Organizations running symfony/security-http in internet-facing or privileged positions face immediate risk.
SENTINEL APEX URGENCY: ELEVATED. Score: 44/100 LOW. Patch before exploitation activity begins.
🎯 MITRE ATT&CK Mapping
| Category | Mapping |
|---|---|
| Primary Tactic | Initial Access |
| Primary Technique | T1190 — Exploit Public-Facing Application |
| Sub-Technique | T1203 — Exploitation for Client Execution |
| Weakness (CWE) | CWE-290 |
| Intel Type | 🔴 CVE ANALYSIS |
| Source(s) | github_advisories |
🔴 CVE Reference
| CVE ID | Reference | Score |
|---|---|---|
| CVE-2026-45063 | NVD → | 7.5 |
| CVE-2026-45063 | NVD → | 7.5 |
🏷️ Indicators of Compromise — Enriched IOC Feed
Normalized IOCs with confidence scoring. Block immediately across all enforcement points. SOC Pro subscribers receive enriched IOC bundles with full attribution and STIX/TAXII feeds.
| Indicator Value | Type | Confidence | First Seen |
|---|---|---|---|
| example.com | domain | 75% | 2026-05-27 |
🔍 Detection Rules — Sigma (SIEM)
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📡 Detection Rules — YARA (Endpoint)
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🛡️ SOC Response Playbook
- 1IMMEDIATE (0-1hr): Identify all instances of symfony/security-http in your environment via CMDB/asset inventory
- 2IMMEDIATE: Block all 1 IOCs in this report at firewall, proxy, DNS, and EDR simultaneously
- 3IMMEDIATE (0-1hr): Apply vendor patch — no maintenance window exception for LOW threats
- 4IMMEDIATE (1-2hr): If no patch available: implement WAF rules, ACLs, or network-level compensating controls
- 5SHORT-TERM (2-4hr): Deploy Sigma detection rule to SIEM — validate alert generation in test environment
- 6SHORT-TERM (4-8hr): Review logs for exploitation indicators (anomalous symfony/security-http requests, error spikes)
- 7SHORT-TERM (8-24hr): Hunt for post-exploitation: new admin accounts, scheduled tasks, lateral movement
- 8MONITOR: Subscribe to composer security advisories for patch updates
- 9ONGOING: Track SENTINEL APEX intelligence feed for follow-on campaigns targeting symfony/security-http
📎 Intelligence References
- github.com/advisories/GHSA-ph86-p8f6-f9r2
- github.com/symfony/symfony/security/advisories/GHSA-ph86-p8f6-f9r2
- github.com/symfony/symfony/commit/ccb3f724c7ff55670a6fe3521c7bf1514cce
- github.com/FriendsOfPHP/security-advisories/blob/master/symfony/securi
- github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfon
- 📌 NVD — CVE-2026-45063
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Report ID: SENTINEL-CVE-2026-45063-2026-05-27 | Priority: 44/100 LOW | Sources: 1
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