dbcve.org
Debian LinuxOperating system · Debian

CVE-2015-2320

CRITICAL · 9.8 CVSS v3.0 Published 2018-01-08
Fix available
A fix is available. Upgrade to 3.12.1 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
The TLS stack in Mono before 3.12.1 allows remote attackers to have unspecified impact via vectors related to client-side SSLv2 fallback.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-295

The application does not properly validate the TLS certificate presented by the other side — skipping the chain, the hostname, or expiry — so an attacker with a forged or mismatched certificate can sit in the middle of a supposedly secure connection. It is a common trap in custom clients and misconfigured libraries. The fix is full certificate validation, and never disabling verification to make errors go away.

General guidance for the improper certificate validation class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Debian LinuxOperating system
Affected:= 7.0
MonoApplication
Affected:< 3.12.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 3.12.1 or later
Fixed in 3.12.1
Vendor patch github.com →
Recommended fix High confidence

Mono 3.12.1 or later (or Debian Linux 8+ with updated packages)

  1. Check the current Mono version installed by running 'mono --version' or examining the package manager
  2. Upgrade Mono to version 3.12.1 or later using the appropriate package manager for your distribution
  3. For Debian 7.0, update the mono-complete package: 'apt-get update && apt-get install mono-complete'
  4. For other distributions, consult the Mono project documentation for installation of version 3.12.1 or newer
  5. After upgrading, verify the new version is installed with 'mono --version'
  6. Test that applications relying on TLS/SSL functionality work correctly after the upgrade
Caveat Upgrading Mono's TLS stack may affect applications that depend on legacy SSLv2 fallback behavior; thoroughly test TLS-dependent applications after upgrading

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $2,300. Get the upgrade done

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2015-2320 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data