CVE-2017-12310
A vulnerability in the auto discovery phase of Cisco Spark Hybrid Calendar Service could allow an unauthenticated, remote attacker to view sensitive information in the unencrypted headers of an HTTP method request.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.89%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
A vulnerability in the auto discovery phase of Cisco Spark Hybrid Calendar Service could allow an unauthenticated, remote attacker to view sensitive information in the unencrypted headers of an HTTP method request. The attacker could use this information to conduct additional reconnaissance attacks leading to the disclosure of sensitive customer data. The vulnerability exists in the auto discovery phase because an unencrypted HTTP request is made due to requirements for implementing the Hybrid Calendar service. An attacker could exploit this vulnerability by monitoring the unencrypted traffic on the network. An exploit could allow the attacker to access sensitive customer data belonging to Office365 users, such as email and calendar events. Cisco Bug IDs: CSCvg35593.
- CVSS 3.0
- 7.5 HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- EPSS
- 0.89% probability · 59th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-200, CWE-319
- Affected
- cisco/spark hybrid calendar service
- Source
- psirt@cisco.com
EPSS 0.9% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.