Security readout for executives and security teams
Plain-English summary
Prism before 1.24 can be slowed dramatically when it highlights specially crafted untrusted text. The impact is service availability, not data theft or tampering. The strongest concern is public-facing editors, previewers, documentation tools, or comment systems that syntax-highlight ASCIIDoc or ERB supplied by users.
Executive priority
Prioritize remediation for internet-facing platforms with user-generated previews or code/documentation editing. For sites using Prism only on trusted static content, urgency is lower, but dependency cleanup remains recommended because the affected version is old and patched.
Technical view
CVE-2021-32723 is a ReDoS issue in PrismJS prism versions before 1.24. Vulnerable ASCIIDoc and ERB language regexes can consume excessive processing time on crafted input. The CVSS vector indicates network reachability, low attack complexity, no privileges, required user interaction, changed scope, and high availability impact only.
Likely exposure
Exposure is likely where Prism <1.24 is bundled in web applications and used to highlight untrusted user-provided ASCIIDoc or ERB. Applications only highlighting trusted content, or using unaffected languages, have lower exposure based on the advisory.
Exploitation context
The bundle does not show CISA KEV listing or cited evidence of active exploitation. Exploitation requires Prism to process attacker-controlled text and likely requires a user or workflow to trigger highlighting. The expected result is resource exhaustion or page/service slowdown.
Researcher notes
Evidence supports a high availability risk, not confidentiality or integrity impact. The advisory names ASCIIDoc and ERB as affected and says other languages are not affected. The source bundle provides patch version and workaround, but no exploit proof, payload details, or active exploitation evidence.
Mitigation direction
- Upgrade PrismJS prism to version 1.24.0 or later.
- If upgrade is delayed, do not highlight untrusted ASCIIDoc or ERB.
- Restrict untrusted highlighting to languages the advisory says are unaffected.
- Rebuild and redeploy bundled frontend assets after updating Prism.
- Check downstream vendor guidance for products that embed Prism.
Validation and detection
- Inventory Prism versions in application dependencies and built assets.
- Identify code paths that highlight user-provided or externally sourced text.
- Confirm whether ASCIIDoc or ERB language components are enabled.
- Verify deployed assets load Prism 1.24.0 or later.
- Review monitoring for unexplained CPU spikes in highlighting workflows.
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.
CWE-400: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-32723 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
- 7.4 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:N/A:H
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:N/AC:L/PR:N/UI:R/S:C/C:N/I:N/A:H2.84Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.4HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/PrismJS/prism/security/advisories/GHSA-gj77-59wh-66hgCVE reference · x_refsource_CONFIRM
- https://github.com/PrismJS/prism/pull/2688CVE reference · x_refsource_MISC
- https://github.com/PrismJS/prism/pull/2774CVE reference · x_refsource_MISC
- https://www.oracle.com/security-alerts/cpujan2022.htmlCVE 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.
Uncontrolled Resource Consumption
Uncontrolled Resource Consumption represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.