CVE-2023-39532

CVE-2023-39532 is a critical-severity vulnerability in Agoric Ses with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Description

SES is a JavaScript environment that allows safe execution of arbitrary programs in Compartments. In version 0.18.0 prior to 0.18.7, 0.17.0 prior to 0.17.1, 0.16.0 prior to 0.16.1, 0.15.0 prior to 0.15.24, 0.14.0 prior to 0.14.5, an 0.13.0 prior to 0.13.5, there is a hole in the confinement of guest applications under SES that may manifest as either the ability to exfiltrate information or execute arbitrary code depending on the configuration and implementation of the surrounding host. Guest program running inside a Compartment with as few as no endowments can gain access to the surrounding host’s dynamic import by using dynamic import after the spread operator, like `{...import(arbitraryModuleSpecifier)}`. On the web or in web extensions, a Content-Security-Policy following ordinary best practices likely mitigates both the risk of exfiltration and execution of arbitrary code, at least limiting the modules that the attacker can import to those that are already part of the application. However, without a Content-Security-Policy, dynamic import can be used to issue HTTP requests for either communication through the URL or for the execution of code reachable from that origin. Within an XS worker, an attacker can use the host’s module system to the extent that the host has been configured. This typically only allows access to module code on the host’s file system and is of limited use to an attacker. Within Node.js, the attacker gains access to Node.js’s module system. Importing the powerful builtins is not useful except insofar as there are side-effects and tempered because dynamic import returns a promise. Spreading a promise into an object renders the promises useless. However, Node.js allows importing data URLs, so this is a clear path to arbitrary execution. Versions 0.18.7, 0.17.1, 0.16.1, 0.15.24, 0.14.5, and 0.13.5 contain a patch for this issue. Some workarounds are available. On the web, providing a suitably constrained Content-Security-Policy mitigates most of the threat. With XS, building a binary that lacks the ability to load modules at runtime mitigates the entirety of the threat. That will look like an implementation of `fxFindModule` in a file like `xsPlatform.c` that calls `fxRejectModuleFile`.

Frequently asked questions

What is CVE-2023-39532?
SES is a JavaScript environment that allows safe execution of arbitrary programs in Compartments. In version 0.18.0 prior to 0.18.7, 0.17.0 prior to 0.17.1, 0.16.0 prior to 0.16.1, 0.15.0 prior to 0.15.24, 0.14.0 prior to 0.14.5, an 0.13.0 prior to 0.13.5, there is a hole in the confinement of guest applications under SES that may manifest as either the ability to exfiltrate information or execute arbitrary code depending on the configuration and implementation of the surrounding host. Guest program running inside a Compartment with as few as no endowments can gain access to the surrounding host’s dynamic import by using dynamic import after the spread operator, like `{...import(arbitraryModuleSpecifier)}`. On the web or in web extensions, a Content-Security-Policy following ordinary best practices likely mitigates both the risk of exfiltration and execution of arbitrary code, at least limiting the modules that the attacker can import to those that are already part of the application. However, without a Content-Security-Policy, dynamic import can be used to issue HTTP requests for either communication through the URL or for the execution of code reachable from that origin. Within an XS worker, an attacker can use the host’s module system to the extent that the host has been configured. This typically only allows access to module code on the host’s file system and is of limited use to an attacker. Within Node.js, the attacker gains access to Node.js’s module system. Importing the powerful builtins is not useful except insofar as there are side-effects and tempered because dynamic import returns a promise. Spreading a promise into an object renders the promises useless. However, Node.js allows importing data URLs, so this is a clear path to arbitrary execution. Versions 0.18.7, 0.17.1, 0.16.1, 0.15.24, 0.14.5, and 0.13.5 contain a patch for this issue. Some workarounds are available. On the web, providing a suitably constrained Content-Security-Policy mitigates most of the threat. With XS, building a binary that lacks the ability to load modules at runtime mitigates the entirety of the threat. That will look like an implementation of `fxFindModule` in a file like `xsPlatform.c` that calls `fxRejectModuleFile`.
How severe is CVE-2023-39532?
CVE-2023-39532 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2023-39532 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (65th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-39532?
CVE-2023-39532 primarily affects Agoric Ses. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-39532?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2023-39532 published?
CVE-2023-39532 was published on 2023-08-08 and last updated on 2026-06-17.

References

Affected products (3)

Other CWE-20 (Improper Input Validation) vulnerabilities

Browse all CWE-20 (Improper Input Validation) vulnerabilities →