CVE-2021-45105 — AI Deep Analysis Summary

Q: Who is affected? (Versions/Components)

📦 **Affected**: Apache Log4j2 versions **2.0-alpha1 to 2.16.0**. ⚠️ **Exception**: Version **2.12.3** is NOT affected. 🌐 **Component**: Java-based logging tool widely used in enterprise apps.

Q: What can hackers do? (Privileges/Data)

🛑 **Impact**: **Denial of Service (DoS)** only. 🚫 **No RCE**: Unlike Log4Shell, this does **not** allow Remote Code Execution or data theft. 💣 **Result**: Server resources exhausted, service unavailable.

Q: Is there a public Exp? (PoC/Wild Exploitation)

💻 **Public Exp?**: **YES**. 📜 **PoC**: `${${::-${::-$${::-$}}}}` 🔗 **Availability**: Multiple GitHub repos (e.g., cckuailong, pravin-pp) host ready-to-use scripts for GET/POST requests.

Q: Is it fixed officially? (Patch/Mitigation)

🛡️ **Official Fix**: **YES**. ✅ **Patched Versions**: Upgrade to **2.17.0** or **2.12.3**. 📝 **Action**: Update the `log4j-core` dependency in your Maven/Gradle config immediately.

Q: Is it urgent? (Priority Suggestion)

🔥 **Urgency**: **HIGH**. ⚡ **Why**: Easy to exploit, no auth required, and PoCs are public. 📉 **Risk**: Service disruption affects business continuity. Patch ASAP to prevent downtime.

Updated May 08, 2026

This is a summary of the AI-generated 10-question deep analysis. The full version (longer answers, follow-up Q&A, related CVEs) requires login. Read the full analysis →

Q1What is this vulnerability? (Essence + Consequences)

🚨 **Essence**: Apache Log4j2 suffers from **uncontrolled recursion** in self-referencing lookups.…

Read full answer (login)

Q2Root Cause? (CWE/Flaw)

🔍 **Root Cause**: **CWE-20** (Improper Input Validation). The flaw lies in how the library handles **self-referencing lookups** without limiting recursion depth.…

Read full answer (login)

Q3Who is affected? (Versions/Components)

📦 **Affected**: Apache Log4j2 versions **2.0-alpha1 to 2.16.0**. <br>⚠️ **Exception**: Version **2.12.3** is NOT affected. <br>🌐 **Component**: Java-based logging tool widely used in enterprise apps.

Q4What can hackers do? (Privileges/Data)

🛑 **Impact**: **Denial of Service (DoS)** only. <br>🚫 **No RCE**: Unlike Log4Shell, this does **not** allow Remote Code Execution or data theft. <br>💣 **Result**: Server resources exhausted, service unavailable.

Q5Is exploitation threshold high? (Auth/Config)

🔓 **Threshold**: **Low**. <br>📡 **Requirement**: No authentication needed.…

Read full answer (login)

Q6Is there a public Exp? (PoC/Wild Exploitation)

💻 **Public Exp?**: **YES**. <br>📜 **PoC**: `${${::-${::-$${::-$}}}}` <br>🔗 **Availability**: Multiple GitHub repos (e.g., cckuailong, pravin-pp) host ready-to-use scripts for GET/POST requests.

Q7How to self-check? (Features/Scanning)

🔎 **Self-Check**: <br>1. Scan for Log4j2 versions **< 2.17.0** (excluding 2.12.3). <br>2. Test with payload: `curl -H 'X-Api-Version: ${${::-${::-$${::-$}}}}' http://target`. <br>3.…

Read full answer (login)

Q8Is it fixed officially? (Patch/Mitigation)

🛡️ **Official Fix**: **YES**. <br>✅ **Patched Versions**: Upgrade to **2.17.0** or **2.12.3**. <br>📝 **Action**: Update the `log4j-core` dependency in your Maven/Gradle config immediately.

Q9What if no patch? (Workaround)

🚧 **No Patch?**: <br>1. **Disable JNDI**: Set `log4j2.formatMsgNoLookups=true`. <br>2. **Input Sanitization**: Filter/escape `${` patterns in all user inputs before logging. <br>3.…

Read full answer (login)

Q10Is it urgent? (Priority Suggestion)

🔥 **Urgency**: **HIGH**. <br>⚡ **Why**: Easy to exploit, no auth required, and PoCs are public. <br>📉 **Risk**: Service disruption affects business continuity. Patch ASAP to prevent downtime.

Continue exploring

Vulnerability detail Full AI analysis (login) Apache Software Foundation CWE-20