CyberSecBulletin
CVE-2022-45064NVD status: Analyzed

Apache Sling Engine: Improper Neutralization of Input During Web Page Generation

CVE-2022-45064 is a critical-severity improper neutralization of input during web page generation vulnerability in Apache Sling Engine from Apache, with a CVSS 3.1 base score of 9.0 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, but only if a user takes part, for example by opening a link or file. The record lists version 2.14.0 as the first without the flaw, so updating Apache Sling Engine to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.12% chance of exploitation within 30 days, higher than 67% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update Apache Sling Engine to 2.14.0 or a later version.
  2. Update sling to 2.14.0 or a later version.
  3. Read the advisory on lists.apache.org for workarounds and exact fixed builds.
  4. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
ApacheApache Sling Enginebefore 2.14.02.14.0
Apacheslingbefore 2.14.02.14.0

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
RequiredA user must take an action such as opening a file or link.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.18.0HighCNA (apache.org)
CVSS 3.19.0CriticalNVD

Official description

The SlingRequestDispatcher doesn't correctly implement the RequestDispatcher API resulting in a generic type of include-based cross-site scripting issues on the Apache Sling level. The vulnerability is exploitable by an attacker that is able to include a resource with specific content-type and control the include path (i.e. writing content). The impact of a successful attack is privilege escalation to administrative power. Please update to Apache Sling Engine >= 2.14.0 and enable the "Check Content-Type overrides" configuration option.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Neutralization of Input During Web Page Generation

The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

How developers prevent this class of flaw

  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples of libraries and frameworks that make it easier to generate properly encoded output include Microsoft's Anti-XSS library, the OWASP ESAPI Encoding module, and Apache Wicket.
  • Understand all the potential areas where untrusted inputs can enter your software: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.
  • For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.

More Improper Neutralization of Input During Web Page Generation vulnerabilities (CWE-79)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Apache Sling Engine

All Apache Sling Engine vulnerabilities

Recent Improper Neutralization of Input During Web Page Generation vulnerabilities

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