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GHSA-xvq6-h898-wcj8 CVE-2023-5967

Mattermost denial of service vulnerability

Medium Go
Severity
4.3 / 10
Medium · CVSS 3.1
Exploit chance (EPSS)
0.51%
Chance of exploitation in the next 30 days. Higher than 43.40% of scored vulnerabilities.
Known exploited
No
Not in CISA's catalog
Weakness
CWE-754 Improper Check for Unusual or Exceptional Conditions
Fix
Available
2 packages have a fixed version

Description

Mattermost fails to properly validate requests to the Calls plugin, allowing an attacker sending a request without a User Agent header to cause a panic and crash the Calls plugin

Affected versions

Go

PackageVulnerableFixed in
github.com/mattermost/mattermost-server/v6
< 7.8.12
7.8.12
github.com/mattermost/mattermost/server/v8
>= 8.0.0, < 8.0.4
8.0.4
github.com/mattermost/mattermost/server/v8
>= 8.1.0, < 8.1.3
8.1.3
github.com/mattermost/mattermost/server/v8
>= 9.0.0, < 9.0.1
9.0.1

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/v6 Go → 7.8.12

go
go get github.com/mattermost/mattermost-server/v6@v7.8.12 && go mod tidy

github.com/mattermost/mattermost/server/v8 Go → 8.0.4

go
go get github.com/mattermost/mattermost/server/v8@v8.0.4 && go mod tidy

Severity breakdown

CVSS 3.1 4.3

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

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

Weakness

CWE-754: Improper Check for Unusual or Exceptional Conditions

The product does not check or incorrectly checks for unusual or exceptional conditions that are not expected to occur frequently during day to day operation of the product.

How to prevent it
  • Requirements: Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Choose languages with features such as exception handling that force the programmer to anticipate unusual conditions that may generate exceptions. Custom exceptions may need to be developed to handle unusual business-logic conditions. Be careful not to pass sensitive exceptions back to the user (CWE-209, CWE-248).
  • Implementation: Check the results of all functions that return a value and verify that the value is expected.
  • Implementation: If using exception handling, catch and throw specific exceptions instead of overly-general exceptions (CWE-396, CWE-397). Catch and handle exceptions as locally as possible so that exceptions do not propagate too far up the call stack (CWE-705). Avoid unchecked or uncaught exceptions where feasible (CWE-248).
  • Implementation: Ensure that error messages only contain minimal details that are useful to the intended audience and no one else. The messages need to strike the balance between being too cryptic (which can confuse users) or being too detailed (which may reveal more than intended). The messages should not reveal the methods that were used to determine the error. Attackers can use detailed information to refine or optimize their original attack, thereby increasing their chances of success. If errors must be captured in some detail, record them in log messages, but consider what could occur if the log messages can be viewed by attackers. Highly sensitive information such as passwords should never be saved to log files. Avoid inconsistent messaging that might accidentally tip off an attacker about internal state, such as whether a user account exists or not. Exposing additional information to a potential attacker in the context of an exceptional condition can help the attacker determine what attack vectors are most likely to succeed beyond DoS.
  • Implementation: Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
  • Architecture and Design, Implementation: If the program must fail, ensure that it fails gracefully (fails closed). There may be a temptation to simply let the program fail poorly in cases such as low memory conditions, but an attacker may be able to assert control before the software has fully exited. Alternately, an uncontrolled failure could cause cascading problems with other downstream components; for example, the program could send a signal to a downstream process so the process immediately knows that a problem has occurred and has a better chance of recovery.
  • Architecture and Design: Use system limits, which should help to prevent resource exhaustion. However, the product should still handle low resource conditions since they may still occur.

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/v6
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/v6
GHSA-9p44-r552-4wp9
Mattermost doesn't sanitize the Remote Cluster API response on PATCH operations
Medium Also affects github.com/mattermost/mattermost-server/v6
GHSA-8qq9-cqj8-82w4
Mattermost doesn't sanitize FileInfo.Name received from federated peers during shared channel file sync
High Also affects github.com/mattermost/mattermost-server/v6
GHSA-m2w9-h2mm-79qr
Mattermost doesn't require system-level permission when patching protected default system roles
High Also affects github.com/mattermost/mattermost-server/v6
GHSA-c28q-m4gf-vg4q
Mattermost doesn't enforce PermissionInviteUser when setting AllowOpenInvite or AllowedDomains during team creation
Medium Also affects github.com/mattermost/mattermost-server/v6
GHSA-3vmp-whvv-5v9v
Mattermost doesn't validate that a username returned during bot registration belongs to a bot account
Medium Also affects github.com/mattermost/mattermost-server/v6
GHSA-rp4v-qc77-phm4
Mattermost doesn't restrict role_updated websocket event broadcasts to members of the affected team or channel
Medium Also affects github.com/mattermost/mattermost-server/v6
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