Tl-wdr7660 Firmware: Out-of-bounds Write
CVE-2022-26987 is a high-severity out-of-bounds write vulnerability in Tl-wdr7660 Firmware from TP-Link, 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 Tl-wdr7660 Firmware versions: 2.0.30. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.52% chance of exploitation within 30 days, higher than 75% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of Tl-wdr7660 Firmware you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| TP-Link | Tl-wdr7660 Firmware | 2.0.30 | Not stated |
| TP-Link | Tl-wdr7661 Firmware | Not specified in the record | Not stated |
| TP-Link | Tl-wdr7620 Firmware | Not specified in the record | Not stated |
| TP-Link | Tl-wdr5660 Firmware | Not specified in the record | Not stated |
| Mercusys | Mercury D196g Firmware | 20200109_2.0.4 | Not stated |
| Fastcom | Fac1900r Firmware | 20190827_2.0.2 | Not stated |
Version data comes from NVD's product matching. 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 | 7.8 | High | NVD |
| CVSS 2.0 | 7.2 | High | NVD |
Official description
TP-Link TL-WDR7660 2.0.30, Mercury D196G 20200109_2.0.4, and Fast FAC1900R 20190827_2.0.2 routers have a stack overflow issue in `MmtAtePrase` function. Local users could get remote code execution.
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.
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- github.com/GANGE666Third Party Advisory
Technical write-ups (may include proof of concept)
- drive.google.com/file/d/1SnNoqRlJiBD673UROLwdgg_roMOneVR9/view?usp=sharingExploit, Third Party Advisory
Other vulnerabilities in Tl-wdr7660 Firmware
- 7.8 High severity
Recent Out-of-bounds Write vulnerabilities
- 8.1 High severity
- 9.8 Critical severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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