cs-c6n-a0-1c2wfr-mul_firmware: Out-of-bounds Write
CVE-2023-34552 is a high-severity out-of-bounds write vulnerability in cs-c6n-a0-1c2wfr-mul_firmware from Ezviz, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. The record lists version 5.3.0 as the first without the flaw, so updating cs-c6n-a0-1c2wfr-mul_firmware to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.45% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update cs-c6n-a0-1c2wfr-mul_firmware to 5.3.0 or a later version.
- Update cs-c6n-r101-1g2wf_firmware to 5.3.0 or a later version.
- Update cv310-a0-1b2wfr_firmware to 5.3.0 or a later version.
- Read the advisory on ezviz.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Ezviz | cs-c6n-a0-1c2wfr-mul_firmware | before 5.3.0 | 5.3.0 |
| Ezviz | cs-c6n-r101-1g2wf_firmware | before 5.3.0 | 5.3.0 |
| Ezviz | cv310-a0-1b2wfr_firmware | before 5.3.0 | 5.3.0 |
| Ezviz | Cs-c6n-b0-1g2wf Firmware | 5.3.0 and earlier | Not stated |
| Ezviz | Cs-cv310-a0-1b2wfr Firmware | 5.3.0 and earlier | Not stated |
| Ezviz | Cs-cv310-a0-1c2wfr-c Firmware | 5.3.2 and earlier | Not stated |
| Ezviz | Cs-cv310-a0-3c2wfrl-1080p Firmware | 5.2.7 and earlier | Not stated |
| Ezviz | Cs-cv310-a0-1c2wfr Firmware | 5.3.2 and earlier | Not stated |
| Ezviz | Cs-cv248-a0-32wmfr Firmware | 5.2.3 and earlier | Not stated |
| Ezviz | Lc1c Firmware | 5.3.4 and earlier | 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
- AdjacentThe attacker must be on the same local network segment.
- 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:A/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 | 8.8 | High | NVD |
| CVSS 3.1 | 4.0 | Medium | CISA (ADP) |
Official description
In certain EZVIZ products, two stack based buffer overflows in mulicast_parse_sadp_packet and mulicast_get_pack_type functions of the SADP multicast protocol can allow an unauthenticated attacker present on the same local network as the camera to achieve remote code execution. This affects CS-C6N-B0-1G2WF Firmware versions before V5.3.0 build 230215 and CS-C6N-R101-1G2WF Firmware versions before V5.3.0 build 230215 and CS-CV310-A0-1B2WFR Firmware versions before V5.3.0 build 230221 and CS-CV310-A0-1C2WFR-C Firmware versions before V5.3.2 build 230221 and CS-C6N-A0-1C2WFR-MUL Firmware versions before V5.3.2 build 230218 and CS-CV310-A0-3C2WFRL-1080p Firmware versions before V5.2.7 build 230302 and CS-CV310-A0-1C2WFR Wifi IP66 2.8mm 1080p Firmware versions before V5.3.2 build 230214 and CS-CV248-A0-32WMFR Firmware versions before V5.2.3 build 230217 and EZVIZ LC1C Firmware versions before V5.3.4 build 230214.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Write
The product writes data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega, and the Strsafe.h library from Microsoft. These libraries provide safer versions of overflow-prone string-handling functions.
- 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.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other vulnerabilities in cs-c6n-a0-1c2wfr-mul_firmware
- 8.0 High severity
Recent Out-of-bounds Write vulnerabilities
- 8.8 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 7.5 High severity
- 7.5 High severity
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