GHSA-c2g2-gx4j-rj3j
Slack integration leaks sensitive information in logs
Packages
Details
As written in the advisory (Markdown source, shown as plain text).
### Impact
Sentry's Slack integration incorrectly records the incoming request body in logs. This request data can contain sensitive information, including the [deprecated Slack verification token](https://api.slack.com/authentication/verifying-requests-from-slack#deprecation). With this verification token, it is possible under specific configurations, an attacker can forge requests and act as the Slack integration.
The request body is leaked in log entries matching `event == "slack.*" && name == "sentry.integrations.slack" && request_data == *`. The deprecated slack verification token, will be found in the `request_data.token` key.
Example event:
```json
{
"name": "sentry.integrations.slack",
"level": "info",
"event": "slack.event.message", # This could be any of the `slack.*` events
"request_data": {
# Other keys are omitted for brevity
"token": "<MyDeprecatedSlackVerificationToken>",
}
}
```
### Patches
- **SaaS users** do not need to take any action.
- **Self-hosted users** should upgrade to version 24.5.0 or higher, [rotate their Slack verification token](https://api.slack.com/authentication/verifying-requests-from-slack#regenerating), and [use the Slack Signing Secret instead of the verification token](https://develop.sentry.dev/integrations/slack/).
- If you are only using the `slack.signing-secret` in your self-hosted configuration, then the legacy verification token is not used to verify the webhook payload. It is ignored.
> ⚠️ Sentry's support for validating Slack requests via the legacy verification token will be deprecated in version 24.7.0.
### Workarounds
#### Option 1
Set the `slack.signing-secret` instead of `slack.verification-token`. The [signing secret](https://api.slack.com/authentication/verifying-requests-from-slack#app-management-updates) is Slack's recommended way of authenticating webhooks.
By having `slack.singing-secret` set, Sentry self-hosted will no longer use the verification token for authentication of the webhooks, regardless of whether `slack.verification-token` is set or not.
#### Option 2
The deprecated Slack verification token is leaked in log levels of `INFO` and `ERROR` in the Slack integration. If the self-hosted instance is unable to be upgraded or re-configured to use the `slack.signing-secret`, the logging configuration can be adjusted to not generate logs from the integration. The [default logging configuration can be found in `src/sentry/conf/server.py`](https://github.com/getsentry/sentry/blob/17d2b87e39ccd57e11da4deed62971ff306253d1/src/sentry/conf/server.py#L1307). **Services should be restarted once the configuration change is saved.**
Below you'll find an example of the configuration adjustments necessary to remove the Slack integration logs:
```python
# src/sentry/conf/server.py
...
LOGGING: LoggingConfig = {
...
handlers: {
# the line below already exists in the default configuration
"null": {"class": "logging.NullHandler"},
...
},
"loggers": {
"sentry.integrations.slack": {
"handlers": ["null"], # route logs to null handler
"level": "CRITICAL", # prevent generation of logs a lower levels (ex. ERROR and INFO)
},
...
},
}
```
### References
- https://github.com/getsentry/sentry/pull/70508
- [Sentry Slack Integration Documentation for Self-Hosted users](https://develop.sentry.dev/integrations/slack/)
- [Documentation on Slack Signing Secrets](https://api.slack.com/authentication/verifying-requests-from-slack#app-management-updates)
- [Slack Deprecation for Verification Tokens](https://api.slack.com/authentication/verifying-requests-from-slack#deprecation)
References
External links from the advisory. They lead to third-party sites.
- https://github.com/getsentry/sentry/security/advisories/GHSA-c2g2-gx4j-rj3j
- https://nvd.nist.gov/vuln/detail/CVE-2024-35196
- https://github.com/getsentry/sentry/pull/70508
- https://api.slack.com/authentication/verifying-requests-from-slack#app-management-updates
- https://api.slack.com/authentication/verifying-requests-from-slack#deprecation
- https://api.slack.com/authentication/verifying-requests-from-slack#regenerating
- https://develop.sentry.dev/integrations/slack
- https://github.com/getsentry/sentry
- https://github.com/getsentry/sentry/blob/17d2b87e39ccd57e11da4deed62971ff306253d1/src/sentry/conf/server.py#L1307