Decompression bomb in ezstd:decompress_using_ddict/2 allows BEAM memory exhaustion via unbounded output buffer
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
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| silviucpp | ezstd | unaffected |
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| silviucpp | ezstd | unaffected |
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| Silviucpp | Ezstd |
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| Silviucpp | Ezstd |
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Vendor Workaround
Replace calls to ezstd:decompress_using_ddict/2 with the streaming API: create a context with ezstd:create_decompression_context/1 using a small output buffer, attach the dictionary with ezstd:select_ddict/2, and decompress with ezstd:decompress_streaming/2. The streaming path decompresses into the caller-sized buffer and gives up with {error, decompressor_stuck} after 1000 chunks, so a 64 KiB buffer caps a single call at 64 MiB of output. Treat that error as a rejected input. Legitimate frames whose output exceeds 1000 times the buffer size fail the same way, so size the buffer for the largest expected payload.
No CVSS v3.0
No CVSS v2
This CVE is not in the KEV list.
Exploit prediction score: < 1% (0.178% probability within 30 days)
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cvssV3_1
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| Description | Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in silviucpp ezstd allows an attacker who supplies a zstd frame to ezstd:decompress_using_ddict/2 to exhaust memory and terminate the Erlang VM via a small frame that declares a very large content size. zstd_nif_decompress_using_ddict in c_src/ezstd_nif.cc reads the frame's declared content size with ZSTD_getFrameContentSize and passes it directly to enif_make_new_binary, without the 1 GiB MAX_BUFFER_SIZE check that ezstd:decompress/1 applies before allocating. A valid 65,550-byte frame of RLE blocks declaring 2 GiB is rejected by ezstd:decompress/1 but is fully allocated and decompressed by the dictionary path. The allocation happens inside a NIF, so when it exceeds the memory available to the VM the operating system kills the whole node rather than the calling process. This issue affects ezstd: from 1.0.5 before 1.2.5. | |
| Title | Decompression bomb in ezstd:decompress_using_ddict/2 allows BEAM memory exhaustion via unbounded output buffer | |
| First Time appeared |
Silviucpp
Silviucpp ezstd |
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| Weaknesses | CWE-409 | |
| CPEs | cpe:2.3:a:silviucpp:ezstd:*:*:*:*:*:*:*:* | |
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Silviucpp
Silviucpp ezstd |
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cvssV4_0
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