Adobe ColdFusion Untrusted Data Deserialization Vulnerability (CVE-2023-29300) Remote Code Execution (RCE) Security Advisory
Executive & SecOps Summary
SECOPS ASSESSMENTAdobe ColdFusion versions 2018u16 (and earlier), 2021u6 (and earlier), and 2023.0.0.330468 (and earlier)
Unauthenticated remote attackers can execute arbitrary code with system privileges by sending malicious serialized data
Immediately apply the official Adobe security patch (APSB23-40) and restrict external access to serialization endpoints
Affected Products & Version Scope
Remediation & Live Workaround Commands
PATCH & WORKAROUND1. Official Patch & Version Upgrade Commands
Apply the official security updates provided in Adobe Security Bulletin APSB23-40. Use the ColdFusion Administrator console or execute the following update commands:
# Example script to trigger update installation for ColdFusion 2021/2023
cd /opt/coldfusion2021/cfusion/bin
./cfupdate.sh -install
# Restart the ColdFusion service to apply changes (Linux)
systemctl restart coldfusion20212. Temporary Workaround & Hardening Configuration
If immediate patching is not feasible, block external access to serialization-related endpoints using a Web Application Firewall (WAF) or reverse proxy configuration.
# Nginx configuration to block external access to WDDX and AMF endpoints
server {
listen 80;
server_name your-coldfusion-domain.com;
# Block access to sensitive ColdFusion endpoints
location ~* /(CFIDE|gateway|flex2gateway|flashservices) {
deny all;
return 403;
}
}3. Log Audit & IoC Verification Commands
Verify the running version of ColdFusion and inspect log files for potential exploitation attempts using the following commands:
# Check the installed ColdFusion version and update level
find /opt/coldfusion* -name 'updates.xml' -exec grep -H 'version' {} \;
# Search exception logs for suspicious WDDX or AMF deserialization errors
grep -Ei '(wddx|flex2gateway|flashservices)' /opt/coldfusion*/cfusion/logs/exception.logBlock Exploits Instantly with Managed Virtual Patching Rules
Can't patch production immediately? Deploy managed WAF rules at the edge to intercept RCE, SQLi, and deserialization payloads before they hit your origin server.
Technical Root Cause & Exploitation Mechanics
1. Vulnerability Overview & Root Cause
This vulnerability arises from the Deserialization of Untrusted Data (CWE-502) within Adobe ColdFusion. ColdFusion, which relies on a Java-based architecture, fails to properly validate and sanitize input during the processing of WDDX (Web Distributed Data eXchange) and other object serialization formats. Consequently, when an attacker transmits a crafted serialized object, the application instantiates malicious classes during the deserialization process, leading to arbitrary code execution.
2. Exploitation Mechanics & Attack Scenario
Exploitation of this vulnerability does not require any user interaction or prior authentication. The typical attack scenario unfolds as follows:
- The attacker constructs a malicious serialization payload containing a specific Java gadget chain.
- The attacker sends an HTTP POST request containing this payload to vulnerable endpoints, such as those handling WDDX or AMF (Action Message Format) channels.
- The ColdFusion server deserializes the incoming data without validation, triggering the execution of arbitrary system commands within the JVM context.
3. Infrastructure & Business Impact
With a CVSS score of 9.8 (Critical), this vulnerability is highly severe and is actively exploited in the wild, as confirmed by its inclusion in the CISA KEV catalog. Successful exploitation allows attackers to gain complete control over the ColdFusion server, potentially leading to lateral movement within the internal network, data exfiltration, ransomware deployment, and persistent backdoor installation.
Official Vendor Advisories & References
Adobe ColdFusion versions 2018u16 (and earlier), 2021u6 (and earlier) and 2023.0.0.330468 (and earlier) are affected by a Deserialization of Untrusted Data vulnerability that could result in Arbitrary code execution. Exploitation of this issue does not require user interaction.
Frequently Asked SecOps Questions (CVE-2023-29300)
FAQQ1. How critical is CVE-2023-29300 and is it actively exploited in the wild?
CVE-2023-29300 is rated CVSS 9.8 (CRITICAL) with a 30-day EPSS exploitation probability of 100.0%. It is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, requiring immediate emergency remediation.
Q2. Which vendors and products are affected by CVE-2023-29300?
Primary impacted vendors include adobe across coldfusion. Scope summary: Adobe ColdFusion 2018 Update 16 and earlier, ColdFusion 2021 Update 6 and earlier, and ColdFusion 2023.0.0.330468 and earlier
Q3. What temporary mitigations or workarounds exist for CVE-2023-29300 before patching?
[Mitigation] Immediately apply the official Adobe security patch (APSB23-40) and restrict external access to serialization endpoints Follow the CLI remediation commands and interactive SecOps checklist on this page to restrict exposure prior to your maintenance window.
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