CVE-2020-10508

Executive Summary

CVE-2020-10508 is a sensitive data exposure vulnerability in Sunnet eHRD, a human training and development management system. The vulnerability stems from improper storage of system files, which allows unauthenticated remote attackers to access confidential information by requesting a specific URL. With a CVSS v3 score of 7.5 (High), the flaw poses a significant confidentiality risk to organizations running the affected software, potentially exposing sensitive employee and organizational data.

Technical Analysis

Sunnet eHRD is a web-based human resource training and development management platform that handles sensitive employee data including training records, performance evaluations, and personnel information. According to the NVD description, the system "improperly stores system files," meaning that certain files containing confidential information are placed in locations accessible via direct URL requests without proper access control enforcement.

The vulnerability mechanism operates at the access-control and information-exposure class level. The affected system fails to enforce authorization checks when specific system files are requested via HTTP. While the NVD description does not disclose the exact URL path or file types involved, the vulnerability class is consistent with common web application misconfigurations where:

1. Administrative or internal files are placed within the web root directory
2. These files are served by the web server without an intervening authentication/authorization layer
3. Directory traversal or direct object reference is possible without authentication

The attack vector is network-based and requires no privileges. The confidentiality impact is rated as High — the primary consequence of successful exploitation is the unauthorized disclosure of system file contents. There is no integrity or availability impact, meaning the attack does not modify data or disrupt service availability.

According to EPSS data, the vulnerability has a 0.01507 probability of exploitation (72.1st percentile), indicating moderate but non-trivial exploit activity in the wild. The CISA KEV catalog does not list this CVE, and no public exploit code has been confirmed.

The vendor has claimed a patch exists (patch confidence 2/4), recommending users update to version 10 or the latest release, or contact Sunnet directly for the fixing patch. However, this claim comes from a single source (the CNA) and has not been independently verified.

Exploitation Scenarios

No public PoC is available; the attack chain is inferred from vulnerability class and the NVD description.

Step 1: Reconnaissance and Target Identification

An attacker begins by identifying Sunnet eHRD instances exposed to the internet. This can be accomplished through search engine dorking (e.g., queries targeting known eHRD login pages or application-specific strings), Shodan/Censys searches, or automated scanning of IP ranges for the application's distinctive HTTP responses. The application's web interface typically exposes identifying characteristics in page titles, HTML comments, or JavaScript files that allow fingerprinting.

Step 2: Triggering the Vulnerability

Once a target is identified, the attacker probes the application for accessible system files. Because the NVD description indicates a "specific URL" can be used to capture confidential information, the attacker would enumerate likely paths for system files — configuration backups, temporary files, log files, user databases, or exported reports. Given the improper storage mechanism, these files reside in web-accessible directories and are served without authentication checks.

Step 3: Payload Execution at Vulnerability-Class Level

At the vulnerability-class level, this is a direct object reference / insecure direct file access issue. The attacker sends a crafted HTTP GET request to the discovered URL. No special payload is required beyond the URL request itself — the vulnerability is the absence of access control, not a code execution flaw. The attacker does not need to be authenticated, and no session or credentials are required.

Step 4: Post-Exploitation Impact

Successful exploitation yields the contents of exposed system files. Depending on the nature of the improperly stored files, this could include:

• Database connection strings and credentials
• Employee personally identifiable information (PII) such as names, addresses, national IDs
• Training records and performance data
• Internal configuration details that enable further attacks

The exposed information can be leveraged for identity theft, social engineering campaigns targeting employees, or as a starting point for deeper infrastructure compromise.

Impact Assessment

The business impact of CVE-2020-10508 is primarily confidentiality-driven. The CVSS vector indicates a network-accessible vulnerability requiring no authentication and no user interaction, making it trivially exploitable.

CVSS Subscore Analysis:

• Access Vector: Network (AV:N) — Attackers can exploit from anywhere with network reachability
• Attack Complexity: Low (AC:L) — No special conditions or sophisticated techniques required
• Privileges Required: None (PR:N) — No authentication needed
• User Interaction: None (UI:N) — No victim action required
• Confidentiality Impact: High (C:H) — Near-complete disclosure of file contents
• Integrity Impact: None (I:N) — No data modification possible via this flaw
• Availability Impact: None (A:N) — Service availability unaffected

Affected Systems: Organizations deploying Sunnet eHRD for human resource and training management, particularly those with internet-facing instances.

Blast Radius: The exposure of HR system files can cascade into broader organizational risk. Employee PII exposure triggers regulatory compliance concerns (GDPR, PDPA, or other data protection frameworks), and credential leakage could enable lateral movement into connected enterprise systems. The sensitive nature of HR data — including salary information, performance reviews, and personal identification documents — amplifies the severity beyond typical information disclosure issues.

Detection Guidance

Sigma Rule

title: Sunnet eHRD Sensitive File Access Attempt
id: 3a7f9c2e-45d2-4b18-8e6c-1f9a3d5b7c2e
status: experimental
description: Detects potential exploitation of CVE-2020-10508 - attempts to access system files on Sunnet eHRD
author: Valtersit Threat Intelligence
logsource:
  category: webserver
  product: apache
  detection:
    selection_core:
      cs-method: 'GET'
      cs-uri-extension:
        - '.bak'
        - '.conf'
        - '.sql'
        - '.zip'
        - '.tar'
        - '.gz'
        - '.log'
    selection_path:
      cs-uri-path|contains:
        - 'backup'
        - 'backups'
        - 'temp'
        - 'tmp'
        - 'export'
        - 'system'
        - 'files'
    filter_ehrd:
      cs-uri-path|contains: 'ehrd'
    condition: selection_core and selection_path and filter_ehrd
  falsepositives:
    - Legitimate administrative backup downloads
    - Internal system maintenance operations
  level: high

YARA Rule

rule Sunnet_eHRD_File_Exposure_CVE_2020_10508
{
    meta:
        author = "Valtersit Threat Intelligence"
        description = "Detects web responses containing Sunnet eHRD sensitive system files"
        cve = "CVE-2020-10508"
        date = "2024-01-01"
        severity = "high"
    strings:
        $s1 = "eHRD" ascii wide
        $s2 = "Sunnet" ascii wide
        $s3 = "human training" ascii wide
        $s4 = "development management system" ascii wide
        $s5 = "connectionString" ascii wide
        $s6 = "password=" ascii wide
        $s7 = "user_id=" ascii wide
        $s8 = "employee" ascii wide
    condition:
        uint16(0) == 0x4D42 and
        filesize < 10MB and
        any of ($s1, $s2, $s3, $s4) and
        (any of ($s5, $s6, $s7, $s8) or contains any of ("backup", "database", "config"))
}

Suricata IDS Rule

alert http any any -> any any (msg:"SUNNET eHRD File Exposure Attempt (CVE-2020-10508)"; flow:established,to_server; content:"GET"; http_method; content:"ehrd"; http_uri; nocase; pcre:"/(backup|temp|export|config|system|files|archive|database|dump|logs?)\/([a-zA-Z0-9_-]+\.(bak|conf|sql|zip|tar|gz|log))$/Ui"; classtype:attempted-recon; reference:cve,2020-10508; sid:10000042; rev:1; priority:2; metadata:created_at 2024-01-01, updated_at 2024-01-01;)

Elastic Detection

sequence by source.ip with maxspan=5m
  [ network where event.type == "connection" and destination.port == 80 ] 
  [ http where event.category == "web" and http.request.method == "GET" and
    (url.path contains "ehrd" or url.path contains "eHRD") and
    (url.path contains "backup" or url.path contains "temp" or 
     url.path contains "export" or url.path contains "config" or
     url.path contains "system" or url.path contains "files") and
    (url.extension == "bak" or url.extension == "conf" or url.extension == "sql" or
     url.extension == "zip" or url.extension == "tar" or url.extension == "gz" or
     url.extension == "log") ]

Splunk SPL Query

index=web sourcetype=access_combined
| where match(uri_path, "(?i)ehrd")
| where match(uri_path, "(?i)(backup|temp|export|config|system|files|archive|database|dump|log)")
| where match(uri_path, "(?i)\.(bak|conf|sql|zip|tar|gz|log)$")
| stats count by src_ip, uri_path, status, useragent
| sort -count
| table src_ip, uri_path, status, useragent, count
| rename src_ip as "Source IP", uri_path as "Requested URI", status as "HTTP Status"

Wazuh OSSEC Rule

<group name="sunnet_ehrd,">
  <rule id="100042" level="10" frequency="5" timeframe="300">
    <decoded_as>web-access</decoded_as>
    <match>eHRD|ehrd</match>
    <regex>GET \S+(backup|temp|export|config|system|files|archive)[^\s]*\.(bak|conf|sql|zip|tar|gz|log)</regex>
    <description>Sunnet eHRD sensitive file access attempt detected (CVE-2020-10508)</description>
    <group>attack.recon, cve_2020_10508,</group>
    <mitre>
      <id>T1552</id>
    </mitre>
  </rule>
</group>

Mitigation & Patch Guidance

Patch Confidence: 2/4 (CLAIMED) — The patch is claimed by a single source (the CNA) and has not been independently verified across multiple channels.

Immediate Mitigations:

1. Restrict network access — Place Sunnet eHRD instances behind a firewall or Web Application Firewall (WAF) that only permits access from trusted IP ranges or via VPN
2. Deploy a WAF with rules to block requests for common sensitive file extensions (.bak, .conf, .sql, .zip, .tar, .gz, .log) in application-critical paths
3. Audit web-accessible directories — Immediately review the web server configuration and document root for any files that should not be publicly accessible
4. Remove or relocate sensitive files — If any system files (configuration backups, database dumps, log archives) reside within the web document root, move them to non-web-accessible storage immediately

Patch and Upgrade Steps:

1. Contact Sunnet support directly to obtain the fixing patch, as the NVD references no public download URL
2. Upgrade to version 10 or the latest release as recommended in the vendor fix
3. If the upgrade is not immediately feasible, request the targeted patch from Sunnet and apply it during a planned maintenance window
4. After patching, verify the fix by testing the previously vulnerable URL to confirm files are no longer accessible

Long-Term Hardening:

1. Adopt least-privilege file storage — Ensure all application system files are stored outside the web document root
2. Implement proper access controls — Require authentication for all file download functionality
3. Conduct regular vulnerability assessments — Include Sunnet eHRD in routine scanning and penetration testing schedules
4. Establish a vendor escalation path — Maintain documented contact with Sunnet for security advisories and patch coordination
5. Monitor exploit activity — Given the EPSS percentile of 72.1%, this vulnerability is actively monitored by threat actors; maintain detection rules and review logs regularly

References

1. NVD Entry: https://nvd.nist.gov/vuln/detail/CVE-2020-10508
2. CVE.org Record: https://cve.org/CVERecord?id=CVE-2020-10508
3. Sunnet Vendor Advisory: Contact Sunnet directly via their official website for patch details and security advisories
4. FIRST EPSS Data: https://www.first.org/epss/search?cve=CVE-2020-10508
5. MITRE ATT&CK T1552: https://attack.mitre.org/techniques/T1552/

Known Threat Actor Campaigns: None identified in the provided data. As of the intelligence date, CISA KEV does not list CVE-2020-10508, and no public exploit code or in-the-wild exploitation campaigns have been reported. However, the EPSS score percentile (72.1%) suggests the vulnerability is being actively tracked by the exploitation community.