| タイトル | The Trusted Domain Project OpenDKIM 2.11.0 Improper Input Validation |
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| 説明 | OpenDKIM 2.11.0 incorrectly parses certain RFC-valid values in the DKIM-Signature header. An i= identity containing an additional or escaped at-sign, or a d= domain ending in a trailing dot, can desynchronize the tag tokenizer because it treats characters inside a tag value as structural delimiters instead of parsing the semicolon-separated tag list correctly.
As a result, a cryptographically valid rsa-sha256 signature may be reported as dkim=permerror. OpenDKIM may also emit an incorrect Authentication-Results value such as header.a=rsa-sha1, even though the signature specifies a=rsa-sha256.
The issue can be triggered remotely by a sender using a valid DKIM key for a domain they control. No victim signing key, authentication, or user interaction is required. Legitimate messages using these valid signature forms may fail DKIM and consequently fail DMARC on OpenDKIM-based receivers, causing rejection or quarantine. The incorrect header.a value also compromises the integrity of authentication metadata consumed by downstream policy engines, monitoring systems, and security dashboards. |
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| ソース | ⚠️ https://xuyongzhe-vt.github.io/share/opendkim-tag-parser-desync.html |
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| ユーザー | yongzhe_xu (UID 100420) |
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| 送信 | 2026年08月07日 05:33 (2 月 ago) |
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| モデレーション | 2026年09月28日 13:52 (2 months later) |
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| ステータス | 承諾済み |
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| VulDBエントリ | 411034 [Trusted Domain Project OpenDKIM 迄 2.11.0 Tag Tokenizer dkim.c dkim_process_set] |
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| ポイント | 20 |
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