What is CVE-2017-7921?
CVE-2017-7921 is an improper authentication flaw in certain Hikvision IP camera firmware that can enable unauthorized privilege escalation. Hikvision’s advisory describes the issue as occurring “while processing a specified request code,” allowing an attacker to obtain additional privileges and then acquire or tamper with device information. In practical terms, this can turn an exposed or poorly segmented camera into an entry point for configuration abuse and potential credential exposure, depending on how the device is deployed. The risk is elevated by the fact that CISA’s Known Exploited Vulnerabilities (KEV) catalog lists CVE-2017-7921 as exploited in the wild (added March 5, 2026).
What is Affected By CVE-2017-7921?
CVE-2017-7921 affects specific Hikvision IP camera series running vulnerable firmware build ranges identified by Hikvision. The most authoritative source is Hikvision’s own security notification(s), which provide product families, impacted build ranges, and “resolved” (patched) builds. Affected series and versions called out by Hikvision include:
DS-2CD2xx2F-I Series — V5.2.0 build 140721 to V5.4.0 build 160530 (update to Hikvision “resolved” firmware for your region/model).
DS-2CD2xx0F-I / DS-2CD2xx0 Series — V5.2.0 build 140721 to at least V5.4.0 build 160401 (Hikvision advisories vary slightly by page/region; follow the correct download channel for your device).
DS-2CD2xx2FWD Series — V5.3.1 build 150410 to V5.4.4 build 161125.
DS-2CD4x2xFWD Series — V5.2.0 build 140721 to V5.4.0 build 160414.
DS-2CD4xx5 Series — V5.2.0 build 140721 to V5.4.0 build 160421.
DS-2DEx / DS-2DFx Series — ranges include V5.2.0 build 140805/140807 through V5.4.5 build 160928 (model-dependent).
DS-2CD63xx Series — V5.0.9 build 140305 to V5.3.5 build 160106.
Note: Hikvision publishes more than one advisory page for HSRC-201703-04, and the “resolved” build numbers can differ across firmware branches/regions. Use Hikvision’s official download links for your exact camera model and region to avoid loading incompatible firmware.
Mitigation and Remediation For CVE-2017-7921
The primary remediation for CVE-2017-7921 is to update affected cameras to Hikvision’s resolved firmware for the specific model/region. Hikvision’s advisories list the affected ranges and the corresponding fixed firmware baseline, and they explicitly recommend updating devices with the correct firmware. Because this CVE is listed in CISA’s KEV catalog as exploited in the wild, prioritize patching and validation in environments where cameras are reachable from untrusted networks.
Recommended actions (defense-focused):
Patch/upgrade firmware to Hikvision’s resolved versions for your exact device family (use official Hikvision download channels).
Inventory and verify firmware builds across all Hikvision cameras, including “spares” and rarely accessed sites (warehouses, remote offices).
Remove direct internet exposure: place cameras behind a VPN, firewall, or reverse proxy that enforces strong authentication; restrict management interfaces to admin networks only.
Segment and monitor: isolate camera networks (VLAN/ACLs), and alert on unusual camera management/API traffic (unexpected config/user management requests).
Credential hygiene after patching: rotate camera admin passwords and any shared credentials, especially if devices were historically exposed.
Impact of Successful Exploitation of CVE-2017-7921
Successful exploitation of CVE-2017-7921 can grant an attacker elevated privileges that enable device data access and configuration tampering. Hikvision describes the outcome as unauthorized additional privileges used to acquire or tamper with device information. In real deployments, the most material impacts often involve undermining camera integrity, weakening monitoring coverage, or exposing sensitive configuration details that help lateral movement.
Common impacts include:
Privilege escalation on the camera (attacker gains higher-than-intended permissions).
Configuration manipulation, such as changing network settings, streams, users/roles, or disabling features that support monitoring and incident response.
Sensitive information exposure (device details and potentially account/configuration artifacts, depending on model/configuration and what interfaces are reachable).
Operational disruption, including loss of visibility if cameras are reconfigured, rebooted, or effectively “blinded.”
Follow-on risk: compromised cameras can be used as a foothold to probe adjacent internal systems if the camera network is flat or poorly segmented.
Proof of Concept for CVE-2017-7921
Public PoC code exists, but a safe, non-weaponized approach is to validate exposure by checking firmware build ranges and confirming you are on Hikvision’s resolved releases. For reference and attribution, one public PoC repository is available on GitHub; only use such materials in authorized testing and for defensive validation. Below is a simple offline checker that helps you decide whether a firmware build (formatted as YYMMDD, e.g., 160530) falls into Hikvision’s impacted ranges from the vendor advisory.
# Educational / defensive use only: offline build-range checker for CVE-2017-7921
# Source ranges are based on Hikvision HSRC-201703-04 (region/model differences may apply).
RANGES = {
“DS-2CD2xx2F-I”: {“start”: 140721, “end”: 160530, “fixed_min”: 170123},
“DS-2CD2xx0F-I”: {“start”: 140721, “end”: 160401, “fixed_min”: 170123},
“DS-2CD2xx2FWD”: {“start”: 150410, “end”: 161125, “fixed_min”: 170124},
“DS-2CD4x2xFWD”: {“start”: 140721, “end”: 160414, “fixed_min”: 170228},
“DS-2CD4xx5”: {“start”: 140721, “end”: 160421, “fixed_min”: 170302},
“DS-2DFx”: {“start”: 140805, “end”: 160928, “fixed_min”: 170123},
“DS-2CD63xx”: {“start”: 140305, “end”: 160106, “fixed_min”: 170206},
}
def potentially_vulnerable(series: str, build: int) -> str:
s = RANGES.get(series)
if not s:
return “Unknown series: check Hikvision advisory for your exact model/region.”
if s[“start”] <= build <= s[“end”]:
return f”Potentially vulnerable: update to a resolved firmware (>= {s[‘fixed_min’]}) per Hikvision.”
return “Not in the listed vulnerable build range (still confirm against the exact vendor firmware branch).”
# Example:
# print(potentially_vulnerable(“DS-2CD2xx2F-I”, 160530))
If you need to perform deeper validation during incident response (e.g., confirming whether unauthorized requests can reach sensitive endpoints), consult Hikvision’s guidance first and use published third-party PoCs only within a documented, authorized testing scope.