CVE-2020-8260

Unrestricted File Upload in A vulnerability in the Pulse Connect Secure < 9

Verified by Precogs Threat Research
Last Updated: Dec 18, 2025
Base Score
7.2HIGH

Executive Summary

CVE-2020-8260 is a high severity vulnerability affecting appsec. It is classified as Unrestricted Upload. This vulnerability is actively being exploited in the wild.

Precogs AI Insight

"Pulse Connect Secure contains an uncontrolled resource consumption vulnerability via malformed gzip streams. Attackers send highly compressed payloads (gzip bombs) to exhaust system memory and trigger a denial of service. Precogs Application Security Module tracks input decompression boundaries."

Exploit Probability (EPSS)
High (75.9%)
Public POC
Available
Exploit Probability
Elevated (52%)
Public POC
Actively Exploited
Affected Assets
appsecCWE-434

What is this vulnerability?

CVE-2020-8260 is categorized as a high Unrestricted File Upload flaw with a CVSS base score of 7.2. Based on our vulnerability intelligence, this issue occurs when the application fails to securely handle untrusted data boundaries.

A vulnerability in the Pulse Connect Secure < 9.1R9 admin web interface could allow an authenticated attacker to perform an arbitrary code execution using uncontrolled gzip extraction.

This architectural defect enables adversaries to bypass intended security controls, directly manipulating the application's execution state or data layer. Immediate strategic intervention is required.

Risk Assessment

MetricValue
CVSS Base Score7.2 (HIGH)
Vector StringCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
PublishedOctober 28, 2020
Last ModifiedDecember 18, 2025
Related CWEsCWE-434, CWE-434

Impact on Systems

Data Exfiltration: Attackers can extract sensitive data from backend databases, configuration files, or internal services.

Authentication Bypass: Exploiting this flaw may allow unauthorized access to protected resources and administrative interfaces.

Lateral Movement: Once initial access is gained, attackers can pivot to internal systems and escalate privileges.

How to Fix and Mitigate CVE-2020-8260

  1. Apply Vendor Patches Immediately: This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog. Apply updates per vendor instructions.
  2. Verify Patch Deployment: Confirm all instances are updated using Precogs continuous monitoring.
  3. Review Audit Logs: Investigate historical access logs for indicators of compromise related to this attack surface.
  4. Implement Defense-in-Depth: Deploy WAF rules, network segmentation, and endpoint detection to limit blast radius.

Defending with Precogs AI

Pulse Connect Secure contains an uncontrolled resource consumption vulnerability via malformed gzip streams. Attackers send highly compressed payloads (gzip bombs) to exhaust system memory and trigger a denial of service. Precogs Application Security Module tracks input decompression boundaries.

Use Precogs to continuously scan your codebase, binaries, APIs, and infrastructure for this vulnerability class and related attack patterns. Our AI-powered detection engine combines static analysis with threat intelligence to identify exploitable weaknesses before attackers do.

Start scanning with Precogs →

Vulnerability Code Signature

Attack Data Flow

StageDetail
SourceUser-uploaded file
VectorFile is saved to a web-accessible directory without validation
SinkFile system write operation
ImpactRemote Code Execution (RCE), full system compromise

Vulnerable Code Pattern

// ❌ VULNERABLE: Unrestricted Upload
$target_dir = "uploads/";
$target_file = $target_dir . basename($_FILES["fileToUpload"]["name"]);
// Taint sink: saving file without extension/type validation
move_uploaded_file($_FILES["fileToUpload"]["tmp_name"], $target_file);

Secure Code Pattern

// ✅ SECURE: Validated Upload
$target_dir = "uploads/";
$filename = basename($_FILES["fileToUpload"]["name"]);
$filetype = strtolower(pathinfo($filename, PATHINFO_EXTENSION));

// Sanitized validation: strict allowlist
$allowed_types = array("jpg", "png", "gif");
if (in_array($filetype, $allowed_types)) {
    // Generate safe unique filename
    $safe_filename = uniqid() . "." . $filetype;
    move_uploaded_file($_FILES["fileToUpload"]["tmp_name"], $target_dir . $safe_filename);
}

How Precogs Detects This

Precogs AI Analysis Engine utilizes semantic taint tracking to detect insecure file upload routines and missing extension validation.\n

Related Vulnerabilitiesvia CWE-434

Is your system affected?

Precogs AI detects CVE-2020-8260 in compiled binaries, LLMs, and application layers — even without source code access.