[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$f5OmEri1vXIP0CKixW0oTp8seFzDHBowfkvbNv33AEio":3,"g5a-risk:CVE-2021-21827":120},{"success":4,"data":5,"meta":118},true,{"cveId":6,"title":7,"description":8,"shortDescription":9,"publishedDate":10,"lastModified":11,"cvssScore":12,"cvssVector":13,"cvssMetrics":14,"epssScore":48,"epssPercentile":27,"epssTimeSeries":49,"severity":50,"affectedProducts":51,"affectedProductsCount":57,"references":58,"referencesCount":57,"weaknesses":65,"weaknessesCount":80,"isActivelyExploited":81,"cisaInfo":27,"otxData":27,"relatedBlogPosts":82,"seoMetadata":83,"configurations":108,"relatedVendorCves":116,"notableEvents":117},"CVE-2021-21827","What is CVE-2021-21827?","A heap-based buffer overflow vulnerability exists in the XML Decompression DecodeTreeBlock functionality of AT&T Labs Xmill 0.7. Within `DecodeTreeBlock` which is called during the decompression of an XMI file, a UINT32 is loaded from the file and used as trusted input as the length of a buffer. An attacker can provide a malicious file to trigger this vulnerability.","A heap-based buffer overflow vulnerability exists in the XML Decompression DecodeTreeBlock functionality of AT&T Labs Xmill 0.7. Within `DecodeTreeBlock` whi...","2021-08-20T22:15:07.11","2022-05-31T22:08:37.693",9.8,"CVSS:3.1\u002FAV:N\u002FAC:L\u002FPR:N\u002FUI:N\u002FS:U\u002FC:H\u002FI:H\u002FA:H",{"CVSSMetricV31":15,"CVSSMetricV30":30,"CVSSMetricV2":39,"CVSSMetricV40":27},[16],{"Source":17,"Type":18,"CVSSData":19,"ExploitabilityScore":28,"ImpactScore":29},"nvd@nist.gov","Primary",{"Version":20,"VectorString":13,"AttackVector":21,"AttackComplexity":22,"PrivilegesRequired":23,"UserInteraction":23,"Scope":24,"ConfidentialityImpact":25,"IntegrityImpact":25,"AvailabilityImpact":25,"BaseScore":12,"BaseSeverity":26,"ExploitCodeMaturity":27,"RemediationLevel":27,"ReportConfidence":27,"TemporalScore":27,"TemporalSeverity":27,"ConfidentialityRequirement":27,"IntegrityRequirement":27,"AvailabilityRequirement":25,"ModifiedAttackVector":27,"ModifiedAttackComplexity":27,"ModifiedPrivilegesRequired":27,"ModifiedUserInteraction":27,"ModifiedScope":27,"ModifiedConfidentialityImpact":27,"ModifiedIntegrityImpact":27,"ModifiedAvailabilityImpact":27,"EnvironmentalScore":27,"EnvironmentalSeverity":27},"3.1","NETWORK","LOW","NONE","UNCHANGED","HIGH","CRITICAL",null,3.9,5.9,[31],{"Source":32,"Type":33,"CVSSData":34,"ExploitabilityScore":38,"ImpactScore":29},"talos-cna@cisco.com","Secondary",{"Version":35,"VectorString":36,"AttackVector":21,"AttackComplexity":25,"PrivilegesRequired":23,"UserInteraction":23,"Scope":24,"ConfidentialityImpact":25,"IntegrityImpact":25,"AvailabilityImpact":25,"BaseScore":37,"BaseSeverity":25,"ExploitCodeMaturity":27,"RemediationLevel":27,"ReportConfidence":27,"TemporalScore":27,"TemporalSeverity":27,"ConfidentialityRequirement":27,"IntegrityRequirement":27,"AvailabilityRequirement":27,"ModifiedAttackVector":27,"ModifiedAttackComplexity":27,"ModifiedPrivilegesRequired":27,"ModifiedUserInteraction":27,"ModifiedScope":27,"ModifiedConfidentialityImpact":27,"ModifiedIntegrityImpact":27,"ModifiedAvailabilityImpact":27,"EnvironmentalScore":27,"EnvironmentalSeverity":27},"3.0","CVSS:3.0\u002FAV:N\u002FAC:H\u002FPR:N\u002FUI:N\u002FS:U\u002FC:H\u002FI:H\u002FA:H",8.1,2.2,[40],{"Source":17,"Type":18,"CVSSData":41,"BaseSeverity":25,"ExploitabilityScore":46,"ImpactScore":47,"ACInsufInfo":27,"ObtainAllPrivilege":27,"ObtainUserPrivilege":27,"ObtainOtherPrivilege":27,"UserInteractionRequired":27},{"Version":42,"VectorString":43,"AccessVector":21,"AccessComplexity":22,"Authentication":23,"ConfidentialityImpact":44,"IntegrityImpact":44,"AvailabilityImpact":44,"BaseScore":45,"BaseSeverity":27,"Exploitability":27,"RemediationLevel":27,"ReportConfidence":27,"TemporalScore":27,"CollateralDamagePotential":27,"TargetDistribution":27,"ConfidentialityRequirement":27,"IntegrityRequirement":27,"AvailabilityRequirement":27,"EnvironmentalScore":27},"2.0","AV:N\u002FAC:L\u002FAu:N\u002FC:P\u002FI:P\u002FA:P","PARTIAL",7.5,10,6.4,0.01136,[48,48,48,48,48,48,48],"Critical",[52],{"vendor":53,"product":54,"version":55,"criteria":56,"vulnerable":4},"att","xmill","0.7","cpe:2.3:a:att:xmill:0.7:*:*:*:*:*:*:*",1,[59],{"url":60,"source":61,"tags":62},"https:\u002F\u002Ftalosintelligence.com\u002Fvulnerability_reports\u002FTALOS-2021-1291","Talosintelligence",[63,64],"Exploit","Third Party Advisory",[66,74],{"id":67,"name":68,"description":69,"extendedDescription":70,"status":71,"abstraction":72,"structure":73},"CWE-787","Out-of-bounds Write","The product writes data past the end, or before the beginning, of the intended buffer.","","Draft","Base","Simple",{"id":75,"name":76,"description":77,"extendedDescription":78,"status":79,"abstraction":72,"structure":73},"CWE-120","Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')","The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow.","A buffer overflow condition exists when a product attempts to put more data in a buffer than it can hold, or when it attempts to put data in a memory area outside of the boundaries of a buffer. The simplest type of error, and the most common cause of buffer overflows, is the \"classic\" case in which the product copies the buffer without restricting how much is copied. Other variants exist, but the existence of a classic overflow strongly suggests that the programmer is not considering even the most basic of security protections.","Incomplete",2,false,[],{"title":84,"metaDescription":85,"keywords":86,"canonicalUrl":87,"structuredData":88},"What is CVE-2021-21827? Vulnerability Analysis | Security Advisory | Precursor Intelligence","Comprehensive analysis of CVE-2021-21827, a critical severity cyber security vulnerability from 2021. A heap-based buffer overflow vulnerability exists in th...","CVE-2021-21827, CVE-2021-21827 vulnerability, CVE-2021-21827 security, critical severity vulnerability, cybersecurity, vulnerability analysis, security advisory, CVE database, threat intelligence, security research, vulnerability assessment, cyber threats, 2021, CVSS score, exploit, patch, remediation, att security, xmill vulnerability","\u002Fwhat-is\u002Fcve-2021-21827",{"@context":89,"@type":90,"headline":84,"description":85,"datePublished":10,"dateModified":11,"author":91,"publisher":95,"about":99,"mainEntityOfPage":103,"articleSection":106,"keywords":107},"https:\u002F\u002Fschema.org","TechArticle",{"@type":92,"name":93,"url":94},"Organization","Precursor Intelligence","https:\u002F\u002Fprecursorintelligence.com",{"@type":92,"name":93,"url":94,"logo":96},{"@type":97,"url":98},"ImageObject","https:\u002F\u002Fprecursorintelligence.com\u002Fimg\u002Flogos\u002Feplogo.png",{"@type":100,"name":6,"description":101,"additionalType":102},"Thing","Cybersecurity Vulnerability","https:\u002F\u002Fschema.org\u002FSoftwareBug",{"@type":104,"@id":105},"WebPage","https:\u002F\u002Fprecursorintelligence.com\u002Fwhat-is\u002Fcve-2021-21827","Cybersecurity","CVE-2021-21827, CVE-2021-21827 vulnerability, CVE-2021-21827 security, critical severity vulnerability, cybersecurity, vulnerability analysis, security advisory, CVE database, threat intelligence, security research",[109],{"Operator":27,"Negate":27,"Nodes":110},[111],{"Operator":112,"Negate":27,"CPEMatch":113},"OR",[114],{"Vulnerable":4,"Criteria":56,"MatchCriteriaID":115,"VersionStartExcluding":27,"VersionStartIncluding":27,"VersionEndExcluding":27,"VersionEndIncluding":27},"4CC987F6-AAFA-4CDE-842D-EA7858A3E7F4",[],[],{"lastModified":11,"cacheTime":119,"version":42},1792378931645,{"score":121,"band":122,"action":123,"scoredAt":124},56,"Medium","Plan remediation","2026-10-16T06:51:51.953255+00:00"]