Elastic Elasticsearch 6.5.0

An issue was identified that allowed the unsafe deserialization of java objects from hadoop or spark configuration properties that could have been modified by authenticated users. Elastic would like to thank Yakov Shafranovich, with Amazon Web Services for reporting this issue.

It was identified that malformed scripts used in the script processor of an Ingest Pipeline could cause an Elasticsearch node to crash when calling the Simulate Pipeline API.

An issue was found with how API keys are created with the Fleet-Server service account. When an API key is created with a service account, it is possible that the API key could be created with higher privileges than intended. Using this vulnerability, a compromised Fleet-Server service account could escalate themselves to a super-user.

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.

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.

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.

A Denial of Service flaw was discovered in Elasticsearch. Using this vulnerability, an unauthenticated attacker could forcibly shut down an Elasticsearch node with a specifically formatted network request.

A flaw was discovered in Elasticsearch 7.17.0’s upgrade assistant, in which upgrading from version 6.x to 7.x would disable the in-built protections on the security index, allowing authenticated users with “*†index permissions access to this index.

Elasticsearch before 7.14.0 did not apply document and field level security to searchable snapshots. This could lead to an authenticated user gaining access to information that they are unauthorized to view.

In Elasticsearch versions before 7.13.3 and 6.8.17 an uncontrolled recursion vulnerability that could lead to a denial of service attack was identified in the Elasticsearch Grok parser. A user with the ability to submit arbitrary queries to Elasticsearch could create a malicious Grok query that will crash the Elasticsearch node.

A memory disclosure vulnerability was identified in Elasticsearch 7.10.0 to 7.13.3 error reporting. A user with the ability to submit arbitrary queries to Elasticsearch could submit a malformed query that would result in an error message returned containing previously used portions of a data buffer. This buffer could contain sensitive information such as Elasticsearch documents or authentication details.

In Elasticsearch versions before 7.11.2 and 6.8.15 a document disclosure flaw was found when Document or Field Level Security is used. Search queries do not properly preserve security permissions when executing certain cross-cluster search 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 versions before 7.11.2 and 6.8.15 contain a document disclosure flaw was found in the Elasticsearch suggester and profile API when Document and Field Level Security are enabled. The suggester and profile API are normally disabled for an index when document level security is enabled on the index. Certain queries are able to enable the profiler and suggester which could lead to disclosing the existence of documents and fields the attacker should not be able to view.

A document disclosure flaw was found in Elasticsearch versions after 7.6.0 and before 7.11.0 when Document or Field Level Security is used. Get requests do not properly apply security permissions when executing a query against a recently updated document. This affects documents that have been updated and not yet refreshed in the index. This could result in the search disclosing the existence of documents and fields the attacker should not be able to view.

Elasticsearch versions before 7.10.0 and 6.8.14 have an information disclosure issue when audit logging and the emit_request_body option is enabled. The Elasticsearch audit log could contain sensitive information such as password hashes or authentication tokens. This could allow an Elasticsearch administrator to view these details.

Elasticsearch versions 7.7.0 to 7.10.1 contain an information disclosure flaw in the async search API. Users who execute an async search will improperly store the HTTP headers. An Elasticsearch user with the ability to read the .tasks index could obtain sensitive request headers of other users in the cluster. This issue is fixed in Elasticsearch 7.10.2

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.

In Elasticsearch before 7.9.0 and 6.8.12 a field disclosure flaw was found when running a scrolling search with Field Level Security. If a user runs the same query another more privileged user recently ran, the scrolling search can leak fields that should be hidden. This could result in an attacker gaining additional permissions against a restricted index.

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 versions from 6.7.0 before 6.8.8 and 7.0.0 before 7.6.2 contain a privilege escalation flaw if an attacker is able to create API keys. An attacker who is able to generate an API key can perform a series of steps that result in an API key being generated with elevated privileges.

Elasticsearch versions 7.0.0-7.3.2 and 6.7.0-6.8.3 contain a username disclosure flaw was found in the API Key service. An unauthenticated attacker could send a specially crafted request and determine if a username exists in the Elasticsearch native realm.

A race condition flaw was found in the response headers Elasticsearch versions before 7.2.1 and 6.8.2 returns to a request. On a system with multiple users submitting requests, it could be possible for an attacker to gain access to response header containing sensitive data from another user.

A permission issue was found in Elasticsearch versions before 5.6.15 and 6.6.1 when Field Level Security and Document Level Security are disabled and the _aliases, _shrink, or _split endpoints are used . If the elasticsearch.yml file has xpack.security.dls_fls.enabled set to false, certain permission checks are skipped when users perform one of the actions mentioned above, to make existing data available under a new index/alias name. This could result in an attacker gaining additional permissions against a restricted index.

Elasticsearch Security versions 6.5.0 and 6.5.1 contain an XXE flaw in Machine Learning's find_file_structure API. If a policy allowing external network access has been added to Elasticsearch's Java Security Manager then an attacker could send a specially crafted request capable of leaking content of local files on the Elasticsearch node. This could allow a user to access information that they should not have access to.