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CVE Record

CVE-2022-31099: Uncontrolled Recursion in rulex

rulex is a new, portable, regular expression language. When parsing untrusted rulex expressions, the stack may overflow, possibly enabling a Denial of Service attack. This happens when parsing an expression with several hundred levels of nesting, causing the process to abort immediately. This is a security concern for you, if your service parses untrusted rulex expressions (expressions provided by an untrusted user), and your service becomes unavailable when the process running rulex aborts due to a stack overflow. The crash is fixed in version **0.4.3**. Affected users are advised to update to this version. There are no known workarounds for this issue.

MediumCVSS 6.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2022-31099 can make a service crash if it parses maliciously nested rulex expressions from an untrusted user. The issue affects rulex before 0.4.3 and is primarily an availability risk, not a data theft or data modification issue.

Executive priority

Treat as a targeted availability issue. It is most urgent for customer-facing or multi-tenant services that accept rulex expressions, because a parser crash can make the service unavailable.

Technical view

rulex has uncontrolled recursion during expression parsing. Several hundred nesting levels can overflow the stack and abort the process. The advisory says the crash is fixed in version 0.4.3 and lists no known workarounds.

Likely exposure

Exposure is limited to systems using rulex versions earlier than 0.4.3 where untrusted users can submit rulex expressions for parsing. Internal-only or trusted-expression use reduces practical risk.

Exploitation context

The source bundle does not show known active exploitation, and the CVE is not listed as KEV. The CVSS vector indicates network reachability, low attack complexity, low privileges, no user interaction, and high availability impact.

Researcher notes

The root issue is CWE-674 uncontrolled recursion in parser handling. The evidence supports denial of service through process abort, but not confidentiality or integrity impact. The advisory states no workaround beyond updating.

Mitigation direction

  • Upgrade rulex to version 0.4.3 or newer.
  • Prioritize services that parse user-supplied rulex expressions.
  • If upgrade is delayed, check vendor guidance; no workaround is listed.
  • Avoid parsing untrusted rulex expressions until affected deployments are updated.

Validation and detection

  • Inventory applications and dependencies for rulex versions before 0.4.3.
  • Confirm whether any service parses untrusted rulex expressions.
  • Verify production deployments use rulex 0.4.3 or newer.
  • Review crash logs for stack overflow or aborts during rulex parsing.
Prepared
Confidence
high
Sources
4

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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

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cwe · low confidence lookup

CWE-674: Exact CWE lookup

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cve · low confidence lookup

CVE-2022-31099 mapping review

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
6.5 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Official CVE source material

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.

1CVSS vectors
0Timeline events
0ADP providers
3Source links

CVSS vector scores

1 official score

We 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.

ScoreVersionSeverityVectorExploitImpactSource
6.5CVSS 3.1MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H2.83.6Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

6.5Medium
CVSS 3.1 vector shape for CVE-2022-31099Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
rulex-rsrulex< 0.4.3Listed
Weakness

CWE details

CWE-674

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-674 · source CWE mapping

Uncontrolled Recursion

Uncontrolled Recursion represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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