A vulnerability in the Multipurpose Internet Mail Extensions (MIME) scanner of Cisco AsyncOS Software for Cisco Email Security Appliances (E
A vulnerability in the Multipurpose Internet Mail Extensions (MIME) scanner of Cisco AsyncOS Software for Cisco Email Security Appliances (ESA) and Web Security Appliances (WSA) could allow an unauthenticated, remote attacker to bypass configured user filters on the device. Affected Products: This vulnerability affects all releases prior to the first fixed release of Cisco AsyncOS Software for Cisco ESA and Cisco WSA, both virtual and hardware appliances, that are configured with message or content filters to scan incoming email attachments on the ESA or services scanning content of web access on the WSA. More Information: SCvb91473, CSCvc76500. Known Affected Releases: 10.0.0-203 9.9.9-894 WSA10.0.0-233.
- Published
- Feb 21, 2017
- Updated
- Jun 16, 2026
- EPSS
- 1.9% · 79th percentile
- CWE
- CWE-20
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Report tools
Action score
24
Monitor
Low priority for now.
- CVSS
- 23 / 40 · 5.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 1 / 30 · 1.9%
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| cisco | web security appliance | cpe:2.3:a:cisco:web_security_appliance |
| cisco | email security appliance firmware | cpe:2.3:o:cisco:email_security_appliance_firmware |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- cisco email security appliance firmware10.0.0-082
- cisco email security appliance firmware10.0.0-124
- cisco email security appliance firmware10.0.0-125
- cisco email security appliance firmware10.0.0-203
- cisco email security appliance firmware10.0.0-232
- cisco email security appliance firmware9.9.6-026
- cisco email security appliance firmware9.9.9-894
- cisco web security appliance10.0.0-082
- cisco web security appliance10.0.0-124
- cisco web security appliance10.0.0-125
- cisco web security appliance10.0.0-203
- cisco web security appliance10.0.0-232
Versions reported by the vendor
Affected version ranges reported by the assigning authority (cisco). Independent of NVD's CPE analysis and usually ahead of it.
n/a Cisco AsyncOS Software for Cisco ESA and Cisco WSA
- Cisco AsyncOS Software for Cisco ESA and Cisco WSAaffected
Same product
cisco: all recordsOther highest-scoring records for the same primary product.
- CVE-2021-1359Cisco Web Security Appliance Privilege Escalation Vulnerability36Monitor
- CVE-2015-6298The admin web interface in Cisco AsyncOS 8.x before 8.0.8-113, 8.1.x and 8.5.x before 8.5.3-051, 8.6.x and 8.7.x before 8.7.0-171-LD, and 8.36Monitor
- CVE-2018-0410A vulnerability in the web proxy functionality of Cisco AsyncOS Software for Cisco Web Security Appliances could allow an unauthenticated, r35Monitor
- CVE-2015-6292The proxy-cache implementation in Cisco AsyncOS 8.0.x before 8.0.7-151, 8.1.x and 8.5.x before 8.5.2-004, 8.6.x and 8.7.x before 8.7.0-171-L32Monitor
- CVE-2015-6321Cisco AsyncOS before 8.5.7-042, 9.x before 9.1.0-032, 9.1.x before 9.1.1-023, and 9.5.x and 9.6.x before 9.6.0-042 on Email Security Applian32Monitor
- CVE-2015-6293Cisco AsyncOS 8.x before 8.0.8-113, 8.1.x and 8.5.x before 8.5.3-051, 8.6.x and 8.7.x before 8.7.0-171-LD, and 8.8.x before 8.8.0-085 on Web32Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
No fix version is recorded for this entry. Check the references for vendor advisories.
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- low · data or configuration can be modified
- Availability
- none
Impact can extend beyond the vulnerable component (scope changes).
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Changed
- Confidentiality impact
- None
- Integrity impact
- Low
- Availability impact
- None
Weakness class (CWE)
CWE-20 · Improper Input ValidationCVSS vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Buffer Overflow via Environment VariablesCAPEC-10likelihood: High · High
- Server Side Include (SSI) InjectionCAPEC-101likelihood: High · High
- Cross Zone ScriptingCAPEC-104likelihood: Medium · High
- Command Line Execution through SQL InjectionCAPEC-108likelihood: Low · Very High
- Object Relational Mapping InjectionCAPEC-109likelihood: Low · High
- SQL Injection through SOAP Parameter TamperingCAPEC-110likelihood: High · Very High
- Double EncodingCAPEC-120likelihood: Low · Medium
- Subverting Environment Variable ValuesCAPEC-13likelihood: High · Very High
ATT&CK techniques
- Obfuscated Files or InformationT1027
- Masquerading: Invalid Code SignatureT1036.001
- Steal Web Session CookieT1539
- Subvert Trust Controls: Code SigningT1553.002
- Impair Defenses:Impair Command History LoggingT1562.003
- Hijack Execution Flow:Dynamic Linker HijackingT1574.006
- Hijack Execution Flow:Path Interception by PATH Environment VariableT1574.007
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.
References
- www.securityfocus.com/bid/96239
- www.securitytracker.com/id/1037831
- www.securitytracker.com/id/1037832
- tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170215-asyncos
Vendor advisories and official records. Exploit/PoC links are deliberately left out.