Cisco Secure Endpoint: Heap-based Buffer Overflow
CVE-2025-20128 is a high-severity heap-based buffer overflow vulnerability in Cisco Secure Endpoint from Cisco, 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 Cisco Secure Endpoint versions: 7.0.5; 6.2.19; 7.3.3, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.81% chance of exploitation within 30 days, higher than 79% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Clamav to 1.0.8 or 1.4.2, whichever matches your release line, or a later version.
- Update Secure Endpoint to 1.24.4 or 1.25.1 or 7.5.20 or 8.4.3, whichever matches your release line, or a later version.
- Update Secure Endpoint Private Cloud to 4.2.0 or a later version.
- Read the advisory on blog.clamav.net for workarounds and exact fixed builds.
- 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 |
|---|---|---|---|
| Cisco | Cisco Secure Endpoint | 7.0.5; 6.2.19; 7.3.3; 7.2.13; 6.1.5; 6.3.1; 6.2.5; 7.3.5; and 32 more ranges | Not stated |
| Clamav | Clamav | 1.0.0 up to, but not including, 1.0.8; 1.1.0 up to, but not including, 1.4.2 | 1.0.8, 1.4.2 |
| Cisco | Secure Endpoint | before 1.24.4; before 1.25.1; before 7.5.20; 8.0.1.21160 up to, but not including, 8.4.3 | 1.24.4, 1.25.1, 7.5.20, 8.4.3 |
| Cisco | Secure Endpoint Private Cloud | before 4.2.0 | 4.2.0 |
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
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 5.3 | Medium | CNA (cisco.com) |
| CVSS 3.1 | 7.5 | High | NVD |
Official description
A vulnerability in the Object Linking and Embedding 2 (OLE2) decryption routine of ClamAV could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to an integer underflow in a bounds check that allows for a heap buffer overflow read. An attacker could exploit this vulnerability by submitting a crafted file containing OLE2 content to be scanned by ClamAV on an affected device. A successful exploit could allow the attacker to terminate the ClamAV scanning process, resulting in a DoS condition on the affected software. For a description of this vulnerability, see the . Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Heap-based Buffer Overflow
The product writes past the end of a buffer that was allocated on the heap.
How developers prevent this class of flaw
- Pre-design: Use a language or compiler that performs automatic bounds checking.
- Use an abstraction library to abstract away risky APIs. Not a complete solution.
- 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: partial).
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
Other references
Other vulnerabilities in Cisco Secure Endpoint
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
Recent Heap-based Buffer Overflow vulnerabilities
- 8.2 High severity
- 8.8 High severity
- 8.8 High severity
- 7.8 High severity
- 7.0 High severity
- 7.0 High severity
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