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PatchSiren cyber security CVE debrief

CVE-2016-6188 Alinto CVE debrief

CVE-2016-6188 is a memory-consumption denial-of-service issue affecting SOGo 2.3.7. According to the CVE description and NVD data, repeated attempts to upload a large attachment can leak memory or accumulate temporary-file-related resources, eventually degrading service availability. NVD rates the issue as network exploitable with low attack complexity, requiring low privileges and no user interaction, and assigns a CVSS v3.1 score of 6.5 (medium).

Vendor
Alinto
Product
CVE-2016-6188
CVSS
MEDIUM 6.5
CISA KEV
Not listed in stored evidence
Original CVE published
2017-02-03
Original CVE updated
2026-05-13
Advisory published
2017-02-03
Advisory updated
2026-05-13

Who should care

Administrators and operators running SOGo 2.3.7, especially environments that allow users to upload attachments or expose the service to untrusted authenticated users. Security teams should also care because the impact is availability-only but remotely reachable.

Technical summary

NVD identifies CVE-2016-6188 as CWE-399 (resource management errors) in SOGo 2.3.7. The issue is described as a memory leak tied to attempts to upload large attachments, with temporary files mentioned as part of the failure mode. The referenced vendor advisory and fix point to a code change in the inverse-inc/sogo repository, indicating the defect was addressed in upstream source. NVD lists the vulnerable CPE specifically for alinto:sogo:2.3.7.

Defensive priority

Medium. The issue is remotely reachable and can affect availability, but it is limited to denial of service and requires low privileges. Prioritize it if SOGo 2.3.7 is internet-facing, widely used internally, or handles large/frequent attachment uploads.

Recommended defensive actions

  • Upgrade or patch SOGo to a version that includes the fix referenced by the upstream commit and vendor advisory.
  • Review attachment upload controls and rate limits to reduce repeated large upload attempts that can amplify memory usage.
  • Monitor SOGo process memory and restart behavior for signs of resource exhaustion during upload activity.
  • Restrict access to SOGo to authenticated users only and limit which accounts can perform attachment-heavy workflows.
  • Validate that temporary-file handling and cleanup are functioning correctly after applying the vendor fix.

Evidence notes

All claims are grounded in the supplied NVD record and its referenced materials. The CVE description states a memory leak in SOGo 2.3.7 can be triggered by a large number of attempts to upload a large attachment. NVD classifies the weakness as CWE-399 and provides CVSS v3.1 vector AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H. The record references an oss-security mailing list post, a SecurityFocus entry, a GitHub commit in inverse-inc/sogo, and a SOGo vendor bug report. The CVE was published on 2017-02-03 and later modified on 2026-05-13; those dates are recorded here for context only.

Official resources

The CVE was published by NVD on 2017-02-03, with source metadata also showing a later modification on 2026-05-13. The referenced advisory trail in the CVE record points back to a 2016-07-09 oss-security mailing-list post, which provides the