Package Instance

Privilege Context Switching Error in Elasticsearch
Elasticsearch versions before 6.8.13 and 7.9.2 contain a document disclosure flaw when Document or Field Level Security is used. Search queries do not properly preserve security permissions when executing certain complex queries. This could result in the search disclosing the existence of documents the attacker should not be able to view. This could result in an attacker gaining additional insight into potentially sensitive indices.

Elasticsearch allows insertion of sensitive information into log files when using deprecated URIs
Elasticsearch generally filters out sensitive information and credentials before logging to the audit log. It was found that this filtering was not applied when requests to Elasticsearch use certain deprecated URIs for APIs. The impact of this flaw is that sensitive information such as passwords and tokens might be printed in cleartext in Elasticsearch audit logs. Note that audit logging is disabled by default and needs to be explicitly enabled and even when audit logging is enabled, request bodies that could contain sensitive information are not printed to the audit log unless explicitly configured.

The `_xpack/security` APIs have been deprecated in Elasticsearch 7.x and were entirely removed in 8.0.0 and later. The only way for a client to use them in Elasticsearch 8.0.0 and later is to provide the `Accept: application/json; compatible-with=7` header. Elasticsearch official clients do not use these deprecated APIs.

The list of affected, deprecated APIs, is the following:

`POST /_xpack/security/user/{username}`
`PUT /_xpack/security/user/{username}`
`PUT /_xpack/security/user/{username}/_password`
`POST /_xpack/security/user/{username}/_password`
`PUT /_xpack/security/user/_password`
`POST /_xpack/security/user/_password`
`POST /_xpack/security/oauth2/token`
`DELETE /_xpack/security/oauth2/token`
`POST /_xpack/security/saml/authenticate`

Elasticsearch vulnerable to stack overflow in the search API
A flaw was discovered in Elasticsearch affecting the `_search` API that allowed a specially crafted query string to cause a stack overflow and ultimately a denial of service.

Elasticsearch vulnerable to Uncontrolled Resource Consumption
An issue has been identified with how Elasticsearch handled incoming requests on the HTTP layer. An unauthenticated user could force an Elasticsearch node to exit with an OutOfMemory error by sending a moderate number of malformed HTTP requests. The issue was identified by Elastic Engineering and we have no indication that the issue is known or that it is being exploited in the wild.

Privilege Escalation Flaw in Elasticsearch
The fix for CVE-2020-7009 was found to be incomplete. Elasticsearch versions from 6.7.0 to 6.8.7 and 7.0.0 to 7.6.1 contain a privilege escalation flaw if an attacker is able to create API keys and also authentication tokens. An attacker who is able to generate an API key and an authentication token can perform a series of steps that result in an authentication token being generated with elevated privileges.

Elasticsearch Uncontrolled Resource Consumption vulnerability
A flaw was discovered in Elasticsearch, where processing a document in a deeply nested pipeline on an ingest node could cause the Elasticsearch node to crash.