{ "dataType": "CVE_RECORD", "dataVersion": "5.1", "cveMetadata": { "cveId": "CVE-2025-62496", "assignerOrgId": "14ed7db2-1595-443d-9d34-6215bf890778", "state": "PUBLISHED", "assignerShortName": "Google", "dateReserved": "2025-10-15T08:47:41.878Z", "datePublished": "2025-10-16T15:52:05.654Z", "dateUpdated": "2025-10-16T17:26:25.654Z" }, "containers": { "cna": { "affected": [ { "collectionURL": "https://bellard.org/quickjs/", "defaultStatus": "unaffected", "packageName": "js_bigint_from_string", "product": "QuickJS", "vendor": "QuickJS", "versions": [ { "lessThan": "2025-09-13", "status": "affected", "version": "2025-04-26", "versionType": "date" } ] } ], "credits": [ { "lang": "en", "type": "finder", "value": "Google Big Sleep" } ], "datePublic": "2025-07-24T22:00:00.000Z", "descriptions": [ { "lang": "en", "supportingMedia": [ { "base64": false, "type": "text/html", "value": "

A vulnerability exists in the QuickJS engine's BigInt string parsing logic (js_bigint_from_string) when attempting to create a BigInt from a string with an excessively large number of digits.

The function calculates the necessary number of bits (n_bits) required to store the BigInt using the formula:

$$\\text{n\\_bits} = (\\text{n\\_digits} \\times 27 + 7) / 8 \\quad (\\text{for radix 10})$$

  1. For large input strings (e.g., $79,536,432$ digits or more for base 10), the intermediate calculation $(\\text{n\\_digits} \\times 27 + 7)$ exceeds the maximum value of a standard signed 32-bit integer, resulting in an Integer Overflow.

  2. The resulting n_bits value becomes unexpectedly small or even negative due to this wrap-around.

  3. This flawed n_bits is then used to compute n_limbs, the number of memory \"limbs\" needed for the BigInt object. Since n_bits is too small, the calculated n_limbs is also significantly underestimated.

  4. The function proceeds to allocate a JSBigInt object using this underestimated n_limbs.

  5. When the function later attempts to write the actual BigInt data into the allocated object, the small buffer size is quickly exceeded, leading to a Heap Out-of-Bounds Write as data is written past the end of the allocated r->tab array.


" } ], "value": "A vulnerability exists in the QuickJS engine's BigInt string parsing logic (js_bigint_from_string) when attempting to create a BigInt from a string with an excessively large number of digits.\n\nThe function calculates the necessary number of bits (n_bits) required to store the BigInt using the formula:\n\n$$\\text{n\\_bits} = (\\text{n\\_digits} \\times 27 + 7) / 8 \\quad (\\text{for radix 10})$$\n\n * For large input strings (e.g., $79,536,432$ digits or more for base 10), the intermediate calculation $(\\text{n\\_digits} \\times 27 + 7)$ exceeds the maximum value of a standard signed 32-bit integer, resulting in an Integer Overflow.\n\n\n * The resulting n_bits value becomes unexpectedly small or even negative due to this wrap-around.\n\n\n * This flawed n_bits is then used to compute n_limbs, the number of memory \"limbs\" needed for the BigInt object. Since n_bits is too small, the calculated n_limbs is also significantly underestimated.\n\n\n * The function proceeds to allocate a JSBigInt object using this underestimated n_limbs.\n\n\n * When the function later attempts to write the actual BigInt data into the allocated object, the small buffer size is quickly exceeded, leading to a Heap Out-of-Bounds Write as data is written past the end of the allocated r->tab array." } ], "impacts": [ { "capecId": "CAPEC-175", "descriptions": [ { "lang": "en", "value": "CAPEC-175 Code Inclusion" } ] } ], "metrics": [ { "cvssV4_0": { "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "HIGH", "attackRequirements": "PRESENT", "attackVector": "ADJACENT", "baseScore": 7.1, "baseSeverity": "HIGH", "privilegesRequired": "LOW", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "LOW", "subConfidentialityImpact": "HIGH", "subIntegrityImpact": "HIGH", "userInteraction": "PASSIVE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:A/AC:H/AT:P/PR:L/UI:P/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L", "version": "4.0", "vulnAvailabilityImpact": "LOW", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED" }, "format": "CVSS", "scenarios": [ { "lang": "en", "value": "GENERAL" } ] } ], "problemTypes": [ { "descriptions": [ { "cweId": "CWE-190", "description": "CWE-190 Integer Overflow or Wraparound", "lang": "en", "type": "CWE" } ] } ], "providerMetadata": { "orgId": "14ed7db2-1595-443d-9d34-6215bf890778", "shortName": "Google", "dateUpdated": "2025-10-16T15:52:05.654Z" }, "references": [ { "url": "https://bellard.org/quickjs/Changelog" }, { "url": "https://issuetracker.google.com/434193016" } ], "source": { "discovery": "UNKNOWN" }, "title": "Integer overflow in js_bigint_from_string in QuickJS", "x_generator": { "engine": "Vulnogram 0.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "timestamp": "2025-10-16T17:26:14.998141Z", "id": "CVE-2025-62496", "options": [ { "Exploitation": "poc" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "role": "CISA Coordinator", "version": "2.0.3" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2025-10-16T17:26:25.654Z" } } ] } }