Intercom Broadcasting System: Improper Limitation of a Pathname to a Restricted Directory
CVE-2023-6893 is a high-severity improper limitation of a pathname to a restricted directory vulnerability in Intercom Broadcasting System from Hikvision, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Intercom Broadcasting System versions: 3.0.3_20201113_RELEASE(HIK). The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 70.2% chance of exploitation within 30 days, which is in the top 0.61% of all scored CVEs.
Exploitation in the next 30 days is more likely than not, according to EPSS.
What to do
- Update Intercom Broadcast System to 4.1.0 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 |
|---|---|---|---|
| Hikvision | Intercom Broadcasting System | 3.0.3_20201113_RELEASE(HIK) | Not stated |
| Hikvision | Intercom Broadcast System | 3.0.3 up to, but not including, 4.1.0 | 4.1.0 |
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
- NoneNothing can be modified.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 4.3 | Medium | CNA (vuldb.com) |
| CVSS 3.1 | 7.5 | High | NVD |
| CVSS 2.0 | 3.3 | Low | CNA (vuldb.com) |
Official description
A vulnerability was found in Hikvision Intercom Broadcasting System 3.0.3_20201113_RELEASE(HIK) and classified as problematic. Affected by this issue is some unknown functionality of the file /php/exportrecord.php. The manipulation of the argument downname with the input C:\ICPAS\Wnmp\WWW\php\conversion.php leads to path traversal. The exploit has been disclosed to the public and may be used. Upgrading to version 4.1.0 is able to address this issue. It is recommended to upgrade the affected component. The identifier of this vulnerability is VDB-248252.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Limitation of a Pathname to a Restricted Directory
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
How developers prevent this class of flaw
- For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
- Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth.
More Improper Limitation of a Pathname to a Restricted Directory vulnerabilities (CWE-22)
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- vuldb.com/?ctiid.248252Permissions Required, Third Party Advisory
- vuldb.com/?id.248252Third Party Advisory
Technical write-ups (may include proof of concept)
- github.com/willchen0011/cve/blob/main/download.mdExploit, Third Party Advisory
Other vulnerabilities in Intercom Broadcasting System
- 9.8 Critical severity
Recent Improper Limitation of a Pathname to a Restricted Directory vulnerabilities
- 9.1 Critical severity
- 9.8 Critical severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
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