csaf_microsoft - msrc_cve-2025-68156

msrc_cve-2025-68156

Vulnerability from csaf_microsoft

Published

2025-12-02 00:00

Modified

2025-12-19 01:02

Summary

Expr has Denial of Service via Unbounded Recursion in Builtin Functions

Notes

Additional Resources

To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle

Disclaimer

The information provided in the Microsoft Knowledge Base is provided \"as is\" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.

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{
  "document": {
    "category": "csaf_vex",
    "csaf_version": "2.0",
    "distribution": {
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      "tlp": {
        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
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    "notes": [
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        "text": "To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle",
        "title": "Additional Resources"
      },
      {
        "category": "legal_disclaimer",
        "text": "The information provided in the Microsoft Knowledge Base is provided \\\"as is\\\" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.",
        "title": "Disclaimer"
      }
    ],
    "publisher": {
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      "contact_details": "secure@microsoft.com",
      "name": "Microsoft Security Response Center",
      "namespace": "https://msrc.microsoft.com"
    },
    "references": [
      {
        "category": "self",
        "summary": "CVE-2025-68156 Expr has Denial of Service via Unbounded Recursion in Builtin Functions - VEX",
        "url": "https://msrc.microsoft.com/csaf/vex/2025/msrc_cve-2025-68156.json"
      },
      {
        "category": "external",
        "summary": "Microsoft Support Lifecycle",
        "url": "https://support.microsoft.com/lifecycle"
      },
      {
        "category": "external",
        "summary": "Common Vulnerability Scoring System",
        "url": "https://www.first.org/cvss"
      }
    ],
    "title": "Expr has Denial of Service via Unbounded Recursion in Builtin Functions",
    "tracking": {
      "current_release_date": "2025-12-19T01:02:08.000Z",
      "generator": {
        "date": "2025-12-20T09:08:09.232Z",
        "engine": {
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      "id": "msrc_CVE-2025-68156",
      "initial_release_date": "2025-12-02T00:00:00.000Z",
      "revision_history": [
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  "product_tree": {
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      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_version",
                "name": "2.0",
                "product": {
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                  "product_id": "17086"
                }
              },
              {
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                "name": "3.0",
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            ],
            "category": "product_name",
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          },
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                "product": {
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                  "product_id": "2"
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              },
              {
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                "name": "azl3 coredns 1.11.4-11",
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          "product_id": "17084-3"
        },
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  },
  "vulnerabilities": [
    {
      "cve": "CVE-2025-68156",
      "cwe": {
        "id": "CWE-770",
        "name": "Allocation of Resources Without Limits or Throttling"
      },
      "notes": [
        {
          "category": "general",
          "text": "GitHub_M",
          "title": "Assigning CNA"
        }
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          "17084-1",
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          "summary": "CVE-2025-68156 Expr has Denial of Service via Unbounded Recursion in Builtin Functions - VEX",
          "url": "https://msrc.microsoft.com/csaf/vex/2025/msrc_cve-2025-68156.json"
        }
      ],
      "remediations": [
        {
          "category": "none_available",
          "date": "2025-12-19T01:02:08.000Z",
          "details": "There is no fix available for this vulnerability as of now",
          "product_ids": [
            "17086-2"
          ]
        },
        {
          "category": "none_available",
          "date": "2025-12-19T01:02:08.000Z",
          "details": "There is no fix available for this vulnerability as of now",
          "product_ids": [
            "17084-1"
          ]
        },
        {
          "category": "none_available",
          "date": "2025-12-19T01:02:08.000Z",
          "details": "There is no fix available for this vulnerability as of now",
          "product_ids": [
            "17084-3"
          ]
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "environmentalsScore": 0.0,
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "temporalScore": 7.5,
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          },
          "products": [
            "17086-2",
            "17084-1",
            "17084-3"
          ]
        }
      ],
      "title": "Expr has Denial of Service via Unbounded Recursion in Builtin Functions"
    }
  ]
}

CVE-2025-68156 (GCVE-0-2025-68156)

Vulnerability from cvelistv5

Published

2025-12-16 18:24

Modified

2025-12-16 19:59

Severity ?

7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CWE

CWE-770 - Allocation of Resources Without Limits or Throttling

Summary

Expr is an expression language and expression evaluation for Go. Prior to version 1.17.7, several builtin functions in Expr, including `flatten`, `min`, `max`, `mean`, and `median`, perform recursive traversal over user-provided data structures without enforcing a maximum recursion depth. If the evaluation environment contains deeply nested or cyclic data structures, these functions may recurse indefinitely until exceed the Go runtime stack limit. This results in a stack overflow panic, causing the host application to crash. While exploitability depends on whether an attacker can influence or inject cyclic or pathologically deep data into the evaluation environment, this behavior represents a denial-of-service (DoS) risk and affects overall library robustness. Instead of returning a recoverable evaluation error, the process may terminate unexpectedly. In affected versions, evaluation of expressions that invoke certain builtin functions on untrusted or insufficiently validated data structures can lead to a process-level crash due to stack exhaustion. This issue is most relevant in scenarios where Expr is used to evaluate expressions against externally supplied or dynamically constructed environments; cyclic references (directly or indirectly) can be introduced into arrays, maps, or structs; and there are no application-level safeguards preventing deeply nested input data. In typical use cases with controlled, acyclic data, the issue may not manifest. However, when present, the resulting panic can be used to reliably crash the application, constituting a denial of service. The issue has been fixed in the v1.17.7 versions of Expr. The patch introduces a maximum recursion depth limit for affected builtin functions. When this limit is exceeded, evaluation aborts gracefully and returns a descriptive error instead of panicking. Additionally, the maximum depth can be customized by users via `builtin.MaxDepth`, allowing applications with legitimate deep structures to raise the limit in a controlled manner. Users are strongly encouraged to upgrade to the patched release, which includes both the recursion guard and comprehensive test coverage to prevent regressions. For users who cannot immediately upgrade, some mitigations are recommended. Ensure that evaluation environments cannot contain cyclic references, validate or sanitize externally supplied data structures before passing them to Expr, and/or wrap expression evaluation with panic recovery to prevent a full process crash (as a last-resort defensive measure). These workarounds reduce risk but do not fully eliminate the issue without the patch.

References

URL

Tags

	https://github.com/expr-lang/expr/security/advisories/GHSA-cfpf-hrx2-8rv6	x_refsource_CONFIRM
	https://github.com/expr-lang/expr/pull/870	x_refsource_MISC

Impacted products

	Vendor	Product	Version
	expr-lang	expr	Version: < 1.17.7

Show details on NVD website