Summary
Cross site scripting (XSS) potentially exposing cookies / sessions / localStorage, fixed by sidekiq-unique-jobs
v8.0.7.
Specifically, this is a Reflected (Server-Side), Non-Self, Cross Site Scripting vulnerability, considered a P3 on the BugCrowd taxonomy with the following categorization:
Cross-Site Scripting (XSS) > Reflected > Non-Self
It was initially thought there was a second vulnerability (RCE), but it was a false alarm. Injection is impossible with Redis:
String escaping and NoSQL injection
The Redis protocol has no concept of string escaping, so injection is impossible under normal circumstances using a normal client library. The protocol uses prefixed-length strings and is completely binary safe.
Ref: https://redis.io/docs/management/security/
XSS Vulnerability
Specially crafted GET
request parameters handled by any of the following endpoints of sidekiq-unique-jobs
' "admin" web UI, allow a super-user attacker, or an unwitting, but authorized, victim, who has received a disguised / crafted link, to successfully execute malicious code, which could potentially steal cookies, session data, or local storage data from the app the sidekiq-unique-jobs
web UI is mounted in.
/changelogs
/locks
/expiring_locks
This means if your sidekiq-unique-jobs
web UI is mounted at /sidekiq
, the vulnerable paths are:
/sidekiq/changelogs
/sidekiq/locks
/sidekiq/expiring_locks
XSS vulnerability is an instance of CAPEC-32: XSS Through HTTP Query Strings, which is related to CWE-80. In certain cases where it results in a server error with status 500, it could be considered a vector for uncontrolled resource consumption, given that errors can be much more resource intensive that normal requests, and thus CWE-400 & CWE-754 may also be relevant.
Details
Fix for the XSS vulnerability was released in sidekiq-unique-jobs
v8.0.7.
This is an analogous attack vector to that which affected sidekiq
gem from version v7.0.4 to v7.0.7, and was given identifiers GHSA-h3r8-h5qw-4r35 & CVE-2023-1892.
The vulnerability in sidekiq-unique-jobs
' was not fixed by sidekiq
v7.0.8, nor the more recent sidekiq
v7.2.0 releases; they are similar but unrelated, distinct vulnerabilities in adjacent projects.
Note #1: The admin web UI for sidekiq-unique-jobs
is not protected by any authorization constraint in the default configuration. Auth constraints must be configured by the programmer. It is recommended and expected that users will configure authorization constrains on the "admin" UI. This is not specifically related to the vulnerability but may make users who fail to constrain their "admin" UI even more vulnerable.
Note #2: Most users of the library will not have configured the UI on a sandboxed subdomain, making all their cookies, localStorage data and session secrets vulnerable to exposure. The purpose of a sandboxed subdomain is expressly to prevent leaking sensitive data through XSS attacks.
XSS Fix PR: mhenrixon/sidekiq-unique-jobs#829
PoC
XSS
Use a string like:
%22%3E%3Cimg/src/onerror=alert(document.domain)%3E
as the value for one of the parameters that are handled without escaping.
Reference: https://liveoverflow.com/do-not-use-alert-1-in-xss/
- Visit /sidekiq/changelogs - with a crafted query string like one of the following:
a. Screenshot:
b. filter
is XSS vulnerable: ?filter=%22%3E%3Cimg/src/onerror=alert(document.domain)%3E
c. count
is vulnerable to triggering an application error (status 500), potentially allowing resource exhaustion ?count=%22%3E%3Cimg/src/onerror=alert(document.domain)%3E
- Screenshot:
- Visit /sidekiq/locks - with a crafted query string like one of the following:
a. Screenshot:
b. filter
is XSS vulnerable: ?filter=%22%3E%3Cimg/src/onerror=alert(document.domain)%3E
c. count
is vulnerable to triggering an application error (status 500), potentially allowing resource exhaustion ?count=%22%3E%3Cimg/src/onerror=alert(document.domain)%3E
- Screenshot:
- Visit /sidekiq/expiring_locks - with a crafted query string like one of the following:
a. Screenshot:
b. filter
is XSS vulnerable: ?filter=%22%3E%3Cimg/src/onerror=alert(document.domain)%3E
Impact
This is a vulnerability of critical severity, which impacts many thousands of sites, since sidekiq-unique-jobs
is widely deployed across the industry, with multiple attack vectors.
References
Summary
Cross site scripting (XSS) potentially exposing cookies / sessions / localStorage, fixed by
sidekiq-unique-jobs
v8.0.7.Specifically, this is a Reflected (Server-Side), Non-Self, Cross Site Scripting vulnerability, considered a P3 on the BugCrowd taxonomy with the following categorization:
Cross-Site Scripting (XSS) > Reflected > Non-Self
It was initially thought there was a second vulnerability (RCE), but it was a false alarm. Injection is impossible with Redis:
Ref: https://redis.io/docs/management/security/
XSS Vulnerability
Specially crafted
GET
request parameters handled by any of the following endpoints ofsidekiq-unique-jobs
' "admin" web UI, allow a super-user attacker, or an unwitting, but authorized, victim, who has received a disguised / crafted link, to successfully execute malicious code, which could potentially steal cookies, session data, or local storage data from the app thesidekiq-unique-jobs
web UI is mounted in./changelogs
/locks
/expiring_locks
This means if your
sidekiq-unique-jobs
web UI is mounted at/sidekiq
, the vulnerable paths are:/sidekiq/changelogs
/sidekiq/locks
/sidekiq/expiring_locks
XSS vulnerability is an instance of CAPEC-32: XSS Through HTTP Query Strings, which is related to CWE-80. In certain cases where it results in a server error with status 500, it could be considered a vector for uncontrolled resource consumption, given that errors can be much more resource intensive that normal requests, and thus CWE-400 & CWE-754 may also be relevant.
Details
Fix for the XSS vulnerability was released in
sidekiq-unique-jobs
v8.0.7.This is an analogous attack vector to that which affected
sidekiq
gem from version v7.0.4 to v7.0.7, and was given identifiers GHSA-h3r8-h5qw-4r35 & CVE-2023-1892.The vulnerability in
sidekiq-unique-jobs
' was not fixed bysidekiq
v7.0.8, nor the more recentsidekiq
v7.2.0 releases; they are similar but unrelated, distinct vulnerabilities in adjacent projects.Note #1: The admin web UI for
sidekiq-unique-jobs
is not protected by any authorization constraint in the default configuration. Auth constraints must be configured by the programmer. It is recommended and expected that users will configure authorization constrains on the "admin" UI. This is not specifically related to the vulnerability but may make users who fail to constrain their "admin" UI even more vulnerable.Note #2: Most users of the library will not have configured the UI on a sandboxed subdomain, making all their cookies, localStorage data and session secrets vulnerable to exposure. The purpose of a sandboxed subdomain is expressly to prevent leaking sensitive data through XSS attacks.
XSS Fix PR: mhenrixon/sidekiq-unique-jobs#829
PoC
XSS
Use a string like:
as the value for one of the parameters that are handled without escaping.
Reference: https://liveoverflow.com/do-not-use-alert-1-in-xss/
a. Screenshot:
b.
filter
is XSS vulnerable:?filter=%22%3E%3Cimg/src/onerror=alert(document.domain)%3E
c.
count
is vulnerable to triggering an application error (status 500), potentially allowing resource exhaustion?count=%22%3E%3Cimg/src/onerror=alert(document.domain)%3E
a. Screenshot:
b.
filter
is XSS vulnerable:?filter=%22%3E%3Cimg/src/onerror=alert(document.domain)%3E
c.
count
is vulnerable to triggering an application error (status 500), potentially allowing resource exhaustion?count=%22%3E%3Cimg/src/onerror=alert(document.domain)%3E
a. Screenshot:
b.
filter
is XSS vulnerable:?filter=%22%3E%3Cimg/src/onerror=alert(document.domain)%3E
Impact
This is a vulnerability of critical severity, which impacts many thousands of sites, since
sidekiq-unique-jobs
is widely deployed across the industry, with multiple attack vectors.References