USG FLEX H series uOS firmware: Insufficiently Protected Credentials
CVE-2024-9677 is a high-severity insufficiently protected credentials vulnerability in USG FLEX H series uOS firmware from Zyxel, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. Affected USG FLEX H series uOS firmware versions: <= V1.21. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.15% 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 Uos to 1.30 or a later version.
- Read the advisory on zyxel.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Zyxel | USG FLEX H series uOS firmware | <= V1.21 | Not stated |
| Zyxel | usg_flex_700h_firmware | 1.21 and earlier | Not stated |
| Zyxel | Uos | before 1.30 | 1.30 |
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
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- 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:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 5.5 | Medium | CNA (zyxel.com.tw) |
| CVSS 3.1 | 7.8 | High | NVD |
Official description
The insufficiently protected credentials vulnerability in the CLI command of the USG FLEX H series uOS firmware version V1.21 and earlier versions could allow an authenticated local attacker to gain privilege escalation by stealing the authentication token of a login administrator. Note that this attack could be successful only if the administrator has not logged out.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Insufficiently Protected Credentials
The product transmits or stores authentication credentials, but it uses an insecure method that is susceptible to unauthorized interception and/or retrieval.
How developers prevent this class of flaw
- Use an appropriate security mechanism to protect the credentials.
- Make appropriate use of cryptography to protect the credentials.
- Use industry standards to protect the credentials (e.g. LDAP, keystore, etc.).
More Insufficiently Protected Credentials vulnerabilities (CWE-522)
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 USG FLEX H series uOS firmware
- 7.8 High severity
Recent Insufficiently Protected Credentials vulnerabilities
- 8.4 High severity
- 9.8 Critical severity
- 8.2 High severity
- 8.7 High severity
- 7.5 High severity
- 9.1 Critical severity
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