Security readout for executives and security teams
Plain-English summary
This flaw lets an attacker bypass OWASP ModSecurity CRS response-body detection by requesting very small pieces of a protected response. Sensitive data could be extracted in fragments while the WAF misses the content. The main business risk is confidentiality loss where CRS is relied on to detect or block access to restricted backend data.
Executive priority
Treat this as a high-priority confidentiality issue for internet-facing applications using CRS to protect sensitive responses. Prioritize upgrade and configuration verification over emergency response unless separate evidence shows exploitation in your environment.
Technical view
CVE-2022-39958 is a CRS response body bypass involving repeated HTTP Range requests with small byte ranges. Affected versions include 3.0.x, 3.1.x, 3.2.1, and 3.3.2. The CVSS 3.1 score is 7.5 with network attack vector, no privileges, no user interaction, and high confidentiality impact.
Likely exposure
Organizations using OWASP ModSecurity CRS before 3.2.2 or 3.3.3 are potentially exposed, especially if response-body inspection protects sensitive resources. Fedora, Debian LTS, and Gentoo advisories indicate distribution-packaged deployments also required updates.
Exploitation context
The provided sources do not show CISA KEV listing or confirmed active exploitation. The described issue is remotely reachable and low complexity, but the sources only support the bypass scenario, not observed exploitation in the wild.
Researcher notes
The vulnerability is a detection bypass, not a backend authorization fix. Validate exposure by version and configuration, then review whether protected data could be served in partial responses. Avoid assuming every ModSecurity deployment is affected unless OWASP CRS is present and in an affected version.
Mitigation direction
- Upgrade CRS 3.2.1 to 3.2.2 or CRS 3.3.2 to 3.3.3.
- Move unsupported CRS 3.0.x and 3.1.x deployments to a supported fixed branch.
- Configure CRS paranoia level 3 or higher, per the CRS advisory.
- Apply relevant distribution security updates for Fedora, Debian LTS, or Gentoo packages.
- Check current vendor guidance before applying compensating controls not named in these sources.
Validation and detection
- Inventory all ModSecurity CRS versions across edge, reverse proxy, and WAF deployments.
- Confirm CRS runtime configuration uses paranoia level 3 or higher where feasible.
- Verify package versions against Fedora, Debian LTS, Gentoo, or upstream fixed releases.
- Review WAF and access logs for unusual repeated Range requests to sensitive resources.
- Confirm restricted resources do not rely solely on response-body WAF pattern matching.
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-863: Authorization and privilege behavior lookup
Authorization weaknesses can support privilege escalation and valid-account review, depending on exploit path. 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-2022-39958 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
- 7.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
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:N/S:U/C:H/I:N/A:N3.93.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://coreruleset.org/20220919/crs-version-3-3-3-and-3-2-2-covering-several-cves/CVE reference
- FEDORA-2022-90708b46e3CVE reference · vendor-advisory
- FEDORA-2022-85a85c84b3CVE reference · vendor-advisory
- FEDORA-2022-1fd73a5285CVE reference · vendor-advisory
- [debian-lts-announce] 20230130 [SECURITY] [DLA 3293-1] modsecurity-crs security updateCVE reference · mailing-list
- GLSA-202305-25CVE reference · vendor-advisory
- https://lists.debian.org/debian-lts-announce/2025/08/msg00004.htmlCVE reference
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.
Incorrect Authorization
Incorrect Authorization represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.