FIXING main vul #26
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FIXING main vul #26
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Diebbo
commented
Feb 24, 2025
| memcpy(&decompressed_name[decompressed_index], label, label_size); | ||
| decompressed_index = (uint16_t)(decompressed_index+label_size); | ||
| } | ||
| char *pico_dns_decompress_name(char *name, pico_dns_packet *packet) { |
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function presenting vulns
Closed
scribam
reviewed
Nov 15, 2025
| for (i = 0; i < vector->count; i++) { | ||
| iterator = pico_dns_sd_kv_vector_get(vector, i); | ||
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| if (!iterator || iterator->key){ |
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@Diebbo Did you mean?
Suggested change
| if (!iterator || iterator->key){ | |
| if (!iterator || !iterator->key){ |
scribam
reviewed
Nov 15, 2025
| * Only one pointer is allowed in DNS compression, the pointer is always the | ||
| * last according to the RFC */ | ||
| dns_name_foreach_label_safe(label, name, next, PICO_DNS_NAMEBUF_SIZE) { | ||
| if (!label || (*label & 0xFF) >= PICO_DNS_NAMEBUF_SIZE) { |
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@Diebbo Are these checks necessary?
nameis not a NULL pointer (with your previously added check) solabelwill not be a NULL pointer as well (at least, at the beginning of the loop)- Macro
dns_name_foreach_label_safeensures*label <= 63so, to me,(*label & 0xFF) >= PICO_DNS_NAMEBUF_SIZE)will be always false
Let me know if I missed something or if you have an example that makes these checks relevant
This was referenced Nov 29, 2025
Closed
scribam
reviewed
Dec 13, 2025
| decompressed_index = (uint16_t)(decompressed_index+label_size); | ||
| } | ||
| char *pico_dns_decompress_name(char *name, pico_dns_packet *packet) { | ||
| uint16_t packet_len = sizeof(pico_dns_packet); |
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This is wrong as it does not represent the whole size of the packet but a fixed size corresponding to the size of the dns header (12).
scribam
reviewed
Dec 13, 2025
| ptr = (uint16_t)(ptr | (uint16_t)*(label + 1)); | ||
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| /* Check if the pointer is within the packet */ | ||
| if (ptr >= packet_len) { |
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Unit test "tc_mdns_handle_data_as_questions" fails here because there is compression pointer with an offset >= 12
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