| शीर्षक | musl libc musl 0.8.0 - 1.2.6 Inefficient Algorithmic Complexity |
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| विवरण | An algorithmic complexity DoS vulnerability has been discovered in musl 1.2.6.
The GB18030 4-byte decoder in musl libc's iconv() implementation contains a gap-skipping loop that performs a full linear scan of the gb18030126 lookup table (23,940 entries) on each iteration of an outer loop whose iteration count is input-dependent. For 4-byte sequences whose linear index falls just below the dense CJK Unified Ideographs range, the outer loop executes approximately 20,905 times, resulting in approximately 500 million comparisons per input character.
This allows a remote attacker to cause denial of service via CPU exhaustion by sending a crafted GB18030 payload to any network service that uses musl's iconv() for character encoding conversion. Measured on musl 1.2.6 and 1.2.5: a single 4-byte input character (bytes 0x82 0x35 0x8F 0x33) takes approximately 260ms to decode, compared to approximately 13 microseconds for a benign character — a 19,000x slowdown. A payload of 40kB will take the server ~43 minutes process/decode. |
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| स्रोत | ⚠️ https://www.openwall.com/lists/oss-security/2026/04/03/2 |
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| उपयोगकर्ता | 0x001 (UID 97056) |
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| सबमिशन | 03/04/2026 01:15 PM (3 महीनों पहले) |
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| संयम | 09/04/2026 07:34 PM (6 days later) |
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| स्थिति | स्वीकृत |
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| VulDB प्रविष्टि | 356620 [musl libc तक 1.2.6 GB18030 4-byte Decoder src/locale/iconv.c iconv सेवा अस्वीकार] |
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| अंक | 20 |
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