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GHSA-8q4v-35v6-g8wr CVE-2017-18900 GO-2026-4303

Mattermost Server is vulnerable CSV Injection

Critical Go
Severity
9.8 / 10
Critical · CVSS 3.1
Exploit chance (EPSS)
1.30%
Chance of exploitation in the next 30 days. Higher than 70.35% of scored vulnerabilities.
Known exploited
No
Not in CISA's catalog
Weakness
CWE-1236 Improper Neutralization of Formula Elements in a CSV File
Fix
3.10.3
Upgrade github.com/mattermost/mattermost-server to this version or later

Description

An issue was discovered in Mattermost Server before 4.0.4 and 3.10.3. It allows CSV injection via a compliance report.

Affected versions

Go

PackageVulnerableFixed in
github.com/mattermost/mattermost-server
< 3.10.3
3.10.3
github.com/mattermost/mattermost-server
>= 4.0.0, < 4.0.3
4.0.3
github.com/mattermost/mattermost-server
< 3.10.3+incompatible
>= 4.0.0+incompatible, < 4.0.3+incompatible
3.10.3+incompatible
4.0.3+incompatible

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

github.com/mattermost/mattermost-server Go → 3.10.3

go
go get github.com/mattermost/mattermost-server@v3.10.3 && go mod tidy

Severity breakdown

CVSS 3.1 9.8

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Weakness

CWE-1236: Improper Neutralization of Formula Elements in a CSV File

The product saves user-provided information into a Comma-Separated Value (CSV) file, but it does not neutralize or incorrectly neutralizes special elements that could be interpreted as a command when the file is opened by a spreadsheet product.

How to prevent it
  • Implementation: When generating CSV output, ensure that formula-sensitive metacharacters are effectively escaped or removed from all data before storage in the resultant CSV. Risky characters include '=' (equal), '+' (plus), '-' (minus), and '@' (at).
  • Implementation: If a field starts with a formula character, prepend it with a ' (single apostrophe), which prevents Excel from executing the formula.
  • Architecture and Design: Certain implementations of spreadsheet software might disallow formulas from executing if the file is untrusted, or if the file is not authored by the current user.

References

Timeline

  1. Published
  2. Last updated by the source
  3. Latest EPSS score
AdvisorySeverityWhy it's related
GHSA-xmfh-3ccg-c9fx
Mattermost has an Incorrect Authorization issue
Low Also affects github.com/mattermost/mattermost-server
GHSA-h998-hxxj-8q83
Mattermost doesn't invalidate cached authentication state for active WebSocket connections during global session revocation
Medium Also affects github.com/mattermost/mattermost-server
GHSA-g5vr-6pgg-74qv
Mattermost doesn't enforce bot-specific permission checks on the user active status endpoint
Low Also affects github.com/mattermost/mattermost-server
GHSA-jqgv-39mg-7c2r
Mattermost doesn't authenticate Atlassian Connect installed callbacks, allowing a remote unauthenticated attacker to inject a rogue sharedSecret
Medium Also affects github.com/mattermost/mattermost-server
GHSA-mxq2-5jpg-7474
Mattermost doesn't validate channel ownership of an existing subscription before applying edits
Medium Also affects github.com/mattermost/mattermost-server
GHSA-2g8v-grq3-hq2g
Mattermost doesn't enforce administrator authorization on the {{setDefaultInstance}} call within the {{/gitlab connect}} command handler
Medium Also affects github.com/mattermost/mattermost-server
GHSA-6hxm-w4hv-vgvw
Mattermost doesn't require role-management authorization when setting the scheme_admin flag on group syncable link and patch endpoints
High Also affects github.com/mattermost/mattermost-server
GHSA-9p44-r552-4wp9
Mattermost doesn't sanitize the Remote Cluster API response on PATCH operations
Medium Also affects github.com/mattermost/mattermost-server
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