Cisco Secure Email: Improper Neutralization of Special Elements in Output Used by a Downstream Component
CVE-2024-20429 is a high-severity improper neutralization of special elements in output used by a downstream component vulnerability in Cisco Secure Email from Cisco, with a CVSS 3.1 base score of 7.2 out of 10. It can be exploited remotely over the network by an attacker with administrator privileges, without any action from a user. Affected Cisco Secure Email versions: 11.0.3-238; 11.1.0-069; 11.1.0-131, 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 0.62% chance of exploitation within 30 days, higher than 50% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of Cisco Secure Email you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on sec.cloudapps.cisco.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Cisco | Cisco Secure Email | 11.0.3-238; 11.1.0-069; 11.1.0-131; 11.1.0-128; 12.0.0-419; 12.1.0-071; 12.1.0-087; 12.1.0-089; and 10 more ranges | Not stated |
| Cisco | secure_email | 11.0.3-238; 11.1.0-069; 11.1.0-131; 11.1.0-128; 12.0.0-419; 12.1.0-071; 12.1.0-087; 12.1.0-089; and 10 more ranges | Not stated |
| Cisco | Asyncos | 11.0.3-238; 11.1.0-069; 11.1.0-128; 11.1.0-131; 12.0.0-419; 12.1.0-071; 12.1.0-087; 12.1.0-089; and 10 more ranges | 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
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- HighAdministrator-level access is required first.
- 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:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 6.5 | Medium | CNA (cisco.com) |
| CVSS 3.1 | 7.2 | High | NVD |
Official description
A vulnerability in the web-based management interface of Cisco AsyncOS for Secure Email Gateway could allow an authenticated, remote attacker to execute arbitrary system commands on an affected device. This vulnerability is due to insufficient input validation in certain portions of the web-based management interface. An attacker could exploit this vulnerability by sending a crafted HTTP request to the affected device. A successful exploit could allow the attacker to execute arbitrary commands on the underlying operating system with root privileges. To successfully exploit this vulnerability, an attacker would need at least valid Operator credentials.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Special Elements in Output Used by a Downstream Component
The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.
How developers prevent this class of flaw
- Programming languages and supporting technologies might be chosen which are not subject to these issues.
- Utilize an appropriate mix of allowlist and denylist parsing to filter control-plane syntax from all input.
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 Cisco Secure Email
- 9.8 Critical severity
- 9.8 Critical severity
Cisco Secure Email Gateway SQL Injection Exploited
- 9.8 Critical severity
- 7.5 High severity
- 9.8 Critical severity
- 9.8 Critical severity
Recent Improper Neutralization of Special Elements in Output Used by a Downstream Component vulnerabilities
- 9.8 Critical severity
- 8.8 High severity
- 10.0 Critical severity
- 7.5 High severity
- 9.8 Critical severity
- 9.8 Critical severity
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