CS-CV248: Stack-based Buffer Overflow
CVE-2022-2471 is a critical-severity stack-based buffer overflow vulnerability in CS-CV248 from Ezviz, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 5.2.3 build 220725 as the first without the flaw, so updating CS-CV248 to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.64% chance of exploitation within 30 days, higher than 77% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update CS-CV248 to 5.2.3 build 220725 or a later version.
- Update CS-C6N-A0-1C2WFR to 5.3.0 build 220428 or a later version.
- Update CS-DB1C-A0-1E2W2FR to 5.3.0 build 220802 or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| EZVIZ | CS-CV248 | before 5.2.3 build 220725 | 5.2.3 build 220725 |
| EZVIZ | CS-C6N-A0-1C2WFR | before 5.3.0 build 220428 | 5.3.0 build 220428 |
| EZVIZ | CS-DB1C-A0-1E2W2FR | before 5.3.0 build 220802 | 5.3.0 build 220802 |
| EZVIZ | CS-C6N-B0-1G2WF | before 5.3.0 build 220712 | 5.3.0 build 220712 |
| EZVIZ | CS-C3W-A0-3H4WFRL | before 5.3.5 build 220723 | 5.3.5 build 220723 |
| Ezviz | Cs-c6n-a0-1c2wfr Firmware | 5.3.0 | Not stated |
| Ezviz | Cs-db1c-a0-1e2w2fr Firmware | 5.3.0 | Not stated |
| Ezviz | Cs-c6n-b0-1g2wf Firmware | 5.3.0 | Not stated |
| Ezviz | Cs-c3w-a0-3h4wfrl Firmware | 5.3.5 | Not stated |
| Ezviz | Cs-cv248 Firmware | 5.2.1 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 9.9 | Critical | CNA (bitdefender.com) |
| CVSS 3.1 | 9.8 | Critical | NVD |
Official description
Stack-based Buffer Overflow vulnerability in the EZVIZ Motion Detection component as used in camera models CS-CV248, CS-C6N-A0-1C2WFR, CS-DB1C-A0-1E2W2FR, CS-C6N-B0-1G2WF, CS-C3W-A0-3H4WFRL allows a remote attacker to execute remote code on the device. This issue affects: EZVIZ CS-CV248 versions prior to 5.2.3 build 220725. EZVIZ CS-C6N-A0-1C2WFR versions prior to 5.3.0 build 220428. EZVIZ CS-DB1C-A0-1E2W2FR versions prior to 5.3.0 build 220802. EZVIZ CS-C6N-B0-1G2WF versions prior to 5.3.0 build 220712. EZVIZ CS-C3W-A0-3H4WFRL versions prior to 5.3.5 build 220723.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Stack-based Buffer Overflow
The product writes past the end of a buffer that was allocated on the stack.
How developers prevent this class of flaw
- Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.
- Use an abstraction library to abstract away risky APIs. Not a complete solution.
- Implement and perform bounds checking on input.
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- bitdefender.com/blog/labs/vulnerabilities-identified-in-ezviz-smart-camsThird Party Advisory
Recent Stack-based Buffer Overflow vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 8.1 High severity
- 7.8 High severity
- 7.5 High severity
- 10.0 High severity
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