A vulnerability in the Trust Verification Service (TVS) of Cisco Unified Communications Manager could allow an unauthenticated, remote attac
A vulnerability in the Trust Verification Service (TVS) of Cisco Unified Communications Manager could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper handling of Transport Layer Security (TLS) traffic by the affected software. An attacker could exploit this vulnerability by generating incomplete traffic streams. A successful exploit could allow the attacker to deny access to the TVS for an affected device, resulting in a DoS condition, until an administrator restarts the service. Known Affected Releases 10.0(1.10000.24) 10.5(2.10000.5) 11.0(1.10000.10) 9.1(2.10000.28). Cisco Bug IDs: CSCux21905.
- Published
- Sep 7, 2017
- Updated
- Jun 16, 2026
- EPSS
- 2.3% · 83th percentile
- CWE
- CWE-119
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Report tools
Action score
31
Monitor
Low priority for now.
- CVSS
- 30 / 40 · 7.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 1 / 30 · 2.3%
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| cisco | unified communications manager | cpe:2.3:a:cisco:unified_communications_manager |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- cisco unified communications manager10.0(1.10000.24)
- cisco unified communications manager10.5(2.10000.5)
- cisco unified communications manager11.0(1.10000.10)
- cisco unified communications manager9.1(2.10000.28)
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 Unified Communications Manager
- Cisco Unified Communications Manageraffected
Same product
cisco: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-20230Cisco Unified Communications Manager Server-Side Request Forgery VulnerabilityKEV90Now
- CVE-2026-20045Cisco Unified Communications Products Remote Code Execution VulnerabilityKEV70This week
- CVE-2024-20253A vulnerability in multiple Cisco Unified Communications and Contact Center Solutions products could allow an unauthenticated, remote attack41Plan
- CVE-2011-1643Cisco Unified Communications Manager (aka CUCM, formerly CallManager) 6.x, 7.x before 7.1(5b)su4, 8.0, and 8.5 before 8.5(1)su2 and Cisco Un41Plan
- CVE-2025-20309Cisco Unified Communications Manager Static SSH Credentials Vulnerability40Plan
- CVE-2011-1609SQL injection vulnerability in Cisco Unified Communications Manager (aka CUCM, formerly CallManager) 6.x before 6.1(5)su2, 7.x before 7.1(5)40Plan
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
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-119 · Improper Restriction of Operations within the Bounds of a Memory BufferCVSS vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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
- Overflow BuffersCAPEC-100likelihood: High · Very High
- Buffer ManipulationCAPEC-123likelihood: High · Very High
- Client-side Injection-induced Buffer OverflowCAPEC-14likelihood: Medium · High
- Filter Failure through Buffer OverflowCAPEC-24likelihood: High · High
- MIME ConversionCAPEC-42likelihood: High · High
- Overflow Binary Resource FileCAPEC-44likelihood: High · Very High
- Buffer Overflow via Symbolic LinksCAPEC-45likelihood: High · High
ATT&CK techniques
—
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/100662
- www.securitytracker.com/id/1039286
- quickview.cloudapps.cisco.com/quickview/bug/CSCux21905
- tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170906-ucm
Vendor advisories and official records. Exploit/PoC links are deliberately left out.