joplin: Improper Control of Generation of Code
CVE-2023-45673 is a critical-severity improper control of generation of code vulnerability in joplin from Laurent22, 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. Affected joplin versions: < 2.13.3. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.03% chance of exploitation within 30 days, higher than 64% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update joplin to 2.13.3 or a later version.
- Read the advisory on github.com for workarounds and exact fixed builds.
- 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
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Laurent22 | joplin | < 2.13.3 | Not stated |
| Laurent 22 | joplin | before 2.13.3 | 2.13.3 |
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 system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.9 | High | CNA (github.com) |
| CVSS 3.1 | 9.0 | Critical | NVD |
Official description
Joplin is a free, open source note taking and to-do application. A remote code execution (RCE) vulnerability in affected versions allows clicking on a link in a PDF in an untrusted note to execute arbitrary shell commands. Clicking links in PDFs allows for arbitrary code execution because Joplin desktop: 1. has not disabled top redirection for note viewer iframes, and 2. and has node integration enabled. This is a remote code execution vulnerability that impacts anyone who attaches untrusted PDFs to notes and has the icon enabled. This issue has been addressed in version 2.13.3. Users are advised to upgrade. There are no known workarounds for this vulnerability.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Control of Generation of Code
The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.
How developers prevent this class of flaw
- Refactor your program so that you do not have to dynamically generate code.
- Run your code in a jail or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which code can be executed by your product. Examples include the Unix chroot jail and AppArmor. In general, managed code may provide some protection. This may not be a feasible solution, and it only limits the impact to the operating system; the rest of your application may still be subject to compromise. Be careful to avoid CWE-243 and other weaknesses related to jails.
- Use dynamic tools and techniques that interact with the product using large test suites with many diverse inputs, such as fuzz testing (fuzzing), robustness testing, and fault injection. The product's operation may slow down, but it should not become unstable, crash, or generate incorrect results.
More Improper Control of Generation of Code vulnerabilities (CWE-94)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Other references
- developer.mozilla.org/en-US/docs/Web/HTML/Element/iframe#sandboxTechnical Description
Other vulnerabilities in joplin
- 8.5 High severity
- 8.0 High severity
- 7.6 High severity
- 7.4 High severity
- 7.7 High severity
- 7.0 High severity
Recent Improper Control of Generation of Code vulnerabilities
- 8.0 High severity
- 8.8 High severity
- 10.0 Critical severity
- 8.1 High severity
- 9.8 Critical severity
- 8.8 High severity
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