Listen to this Post
CVE-2020-15778 is a critical command injection vulnerability discovered in the secure copy (scp) client implementation across OpenSSH versions up to 8.3p1.
The core flaw exists within the remote function inside the scp.c source file, which handles administrative file transmissions between connected nodes.
During file transfer requests, the utility processes destination arguments by passing them directly to the underlying remote shell environment.
Because the application fails to adequately sanitize special shell metacharacters, malicious actors can exploit this behavior.
By crafting filenames or directory paths containing backticks or command substitution sequences, an attacker can force arbitrary code execution.
When the client or server parses these malicious arguments during an scp session, the system interprets them as active shell commands.
The injected code runs with the exact privileges of the user executing the file transfer operation on the host system.
This security gap effectively transforms a routine file copy procedure into an avenue for unauthorized system control and access compromise.
Legacy protocols like scp inherently rely on shell evaluation for handling argument transfers, making comprehensive input validation extremely complex.
Vendors previously noted that restricting these anomalous argument transfers risked breaking legacy automation and deployment workflows globally.
Nevertheless, modern security standards strongly advise deprecating scp entirely in favor of more robust and secure protocols like sftp.
System administrators must conduct thorough asset inventories to detect vulnerable client binaries running across enterprise infrastructure.
Remediation efforts require immediate package upgrades or complete migration to safer file transfer alternatives to prevent exploitation.
DailyCVE Form:
Platform: OpenSSH client
Version: Up to 8.3p1
Vulnerability: OS Command Injection
Severity: High rating
date: July 2020
Prediction: July 2020 patch
What Undercode Say:
Analyzing the underlying mechanics of CVE-2020-15778 reveals critical design flaws in legacy command-line parsing routines.
The reliance on raw shell invocation for processing remote arguments introduces severe security risks when interacting with untrusted servers.
Security analysts should monitor process execution trees and network traffic logs for anomalous scp command invocations containing suspicious shell syntax.
Bash commands and codes related to the blog
Check installed OpenSSH version ssh -V Example of vulnerable scp command structure with malicious backticks scp user@remote:/path/to/file `touch /tmp/pwned` ./
Exploit: (Educational Purposes!)
Conceptual PoC demonstration for CVE-2020-15778 command injection vector
Attackers append backtick sequences inside destination path parameters
exploit_payload = "scp user@target:'file <code>id > /tmp/proof</code>' ."
print(f"Executing payload: {exploit_payload}")
Protection: from this CVE
Upgrade OpenSSH client packages to versions newer than 8.3p1 where patches or deprecation warnings are implemented.
Disable the scp protocol entirely across SSH configurations and enforce the use of secure alternatives like sftp or rsync.
Implement strict input validation and monitoring on all automated file transfer scripts within your infrastructure.
Impact:
Successful exploitation grants remote attackers the ability to execute arbitrary system commands with the privileges of the user running the scp utility. This leads to complete confidentiality compromise, data integrity loss, and potential lateral movement across the internal network environment.
🎯Let’s Practice Exploiting & Learn Patching For Free:
🎓 Live Courses & Certifications:
Join Undercode Academy for Verified Certifications
🚀 Request a Custom Project:
Secure, high-velocity infrastructure and disruptive technological engineering. Contact our engineering team for high-tier development and proprietary systems:
[email protected]
💎 Smart Architecture | 🛡️ Secure by Design | ⭐ Trusted by Thousands
Sources:
Reported By: github.com
Extra Source Hub:
Undercode
