Security readout for executives and security teams
Plain-English summary
Calipso's module installation can write files outside the intended extraction directory if a malicious module archive is installed. That could let an attacker overwrite application or system files on hosts running Calipso, creating confidentiality, integrity, and availability risk.
Executive priority
Treat as high priority if calipso is deployed in production or accepts modules from outside a tightly controlled release process. The main business risk is file overwrite on application hosts, which can affect sensitive data, service integrity, or uptime.
Technical view
The sources describe an arbitrary file write, Zip Slip-style issue in calipso affecting all package versions. Archive extraction during module install can traverse paths and overwrite arbitrary filesystem locations. CVSS 3.1 is 7.3 high, with local attack vector and low complexity.
Likely exposure
Exposure is most likely where calipso is installed and its module install functionality processes third-party, user-supplied, or compromised modules. Systems without calipso, or without module installation paths reachable in practice, are not indicated as affected by the provided sources.
Exploitation context
The bundle does not cite active exploitation, and KEV is false. Public references identify the vulnerability class and affected package, but the provided evidence does not name observed attacks, exploit tooling, or a confirmed patched version.
Researcher notes
Evidence is clear on vulnerable behavior but limited on remediation. Validate exposure by confirming calipso presence, module installation paths, archive-handling boundaries, and runtime write permissions. Do not assume active exploitation or a vendor patch from the supplied bundle.
Mitigation direction
- Inventory systems and applications for the calipso package.
- Avoid installing untrusted or unaudited calipso modules.
- Restrict filesystem permissions for the calipso runtime account.
- Monitor vendor, Snyk, and repository guidance for a confirmed fix.
- Retire or isolate calipso deployments where module installation cannot be controlled.
Validation and detection
- Check dependency manifests and runtime hosts for calipso usage.
- Review whether module installation is enabled or operationally used.
- Identify who can supply or trigger module installation.
- Inspect calipso runtime permissions and writable filesystem paths.
- Review logs for unexpected module installs or file changes.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
File access behavior lookup
The CVE wording references file access or upload behavior, so file telemetry and web shell review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-23391 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L/E:F/RL:U/RC:C
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L/E:F/RL:U/RC:C2.54.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.3HighVector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L/E:F/RL:U/RC:C
Source materials
- CVE List V5 sourceCVE List V5
- https://snyk.io/vuln/SNYK-JS-CALIPSO-1300555CVE reference · x_refsource_MISC
- https://github.com/cliftonc/calipsoCVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.