poetry: Improper Neutralization of Argument Delimiters in a Command
CVE-2022-36069 is a high-severity improper neutralization of argument delimiters in a command vulnerability in poetry from Python-poetry, with a CVSS 3.1 base score of 7.3 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, but only if a user takes part, for example by opening a link or file. Affected poetry versions: < 1.1.9. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.32% chance of exploitation within 30 days, higher than 71% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of poetry you run against the affected versions below, and install the vendor's latest release.
- 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 |
|---|---|---|---|
| Python-poetry | poetry | < 1.1.9 | Not stated |
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
- LocalThe attacker needs local access or must trick a user into running something.
- 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
- UnchangedImpact stays within the vulnerable component.
- 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:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.3 | High | CNA (github.com) |
| CVSS 3.1 | 7.3 | High | NVD |
Official description
Poetry is a dependency manager for Python. When handling dependencies that come from a Git repository instead of a registry, Poetry uses various commands, such as `git clone`. These commands are constructed using user input (e.g. the repository URL). When building the commands, Poetry correctly avoids Command Injection vulnerabilities by passing an array of arguments instead of a command string. However, there is the possibility that a user input starts with a dash (`-`) and is therefore treated as an optional argument instead of a positional one. This can lead to Code Execution because some of the commands have options that can be leveraged to run arbitrary executables. If a developer is exploited, the attacker could steal credentials or persist their access. If the exploit happens on a server, the attackers could use their access to attack other internal systems. Since this vulnerability requires a fair amount of user interaction, it is not as dangerous as a remotely exploitable one. However, it still puts developers at risk when dealing with untrusted files in a way they think is safe, because the exploit still works when the victim tries to make sure nothing can happen, e.g. by vetting any Git or Poetry config files that might be present in the directory. Versions 1.1.9 and 1.2.0b1 contain patches for this issue.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Argument Delimiters in a Command
The product constructs a string for a command to be executed by a separate component in another control sphere, but it does not properly delimit the intended arguments, options, or switches within that command string.
How developers prevent this class of flaw
- Understand all the potential areas where untrusted inputs can enter your product: parameters or arguments, cookies, anything read from the network, environment variables, request headers as well as content, URL components, e-mail, files, databases, and any external systems that provide data to the application. Perform input validation at well-defined interfaces.
- Directly convert your input type into the expected data type, such as using a conversion function that translates a string into a number. After converting to the expected data type, ensure that the input's values fall within the expected range of allowable values and that multi-field consistencies are maintained.
- When exchanging data between components, ensure that both components are using the same character encoding. Ensure that the proper encoding is applied at each interface. Explicitly set the encoding you are using whenever the protocol allows you to do so.
More Improper Neutralization of Argument Delimiters in a Command vulnerabilities (CWE-88)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- github.com/python-poetry/poetry/releases/tag/1.1.9Release Notes
- github.com/python-poetry/poetry/releases/tag/1.2.0b1Release Notes
Other references
Other vulnerabilities in poetry
- 8.7 High severity
- 7.3 High severity
- 9.8 Critical severity
Recent Improper Neutralization of Argument Delimiters in a Command vulnerabilities
- 9.1 Critical severity
- 7.8 High severity
- 8.1 High severity
- 9.8 Critical severity
- 7.5 High severity
- 9.8 Critical severity
Spotted an error? Tell us.