Category

C

Security vulnerabilities and automated fixes for c issues

75 posts found

critical4 min

SGX Enclave ecall_store_data memcpy Buffer Overflow in 256-Byte

The Intel SGX enclave's trusted bridge functions `ecall_store_data` and `ecall_retrieve_data` used `memcpy()` to move data into and out of a fixed 256-byte `secure_storage` buffer without validating that `data_len` fit within destination boundaries. An attacker providing oversized `data_len` values could corrupt enclave memory, breaking SGX's confidentiality guarantees.

#buffer-overflow#sgx#enclave+4 more
A
anupamme
Sep 29, 2026
critical8 min

How NULL pointer dereference from unchecked malloc() happens in C and how to fix it

A critical memory safety vulnerability was discovered in `bench/tokenizer/tokenizer.c` where `malloc()` was called without checking its return value before passing the pointer to `memcpy()`. If allocation fails and `malloc()` returns NULL, the subsequent `memcpy()` writes to address zero, causing heap corruption or potential arbitrary code execution. The fix adds a single NULL check immediately after allocation, exiting cleanly on failure rather than proceeding with a dangerously invalid pointer

#memory-safety#c#null-pointer-dereference+2 more
A
anupamme
Aug 28, 2026
critical7 min

How Stack Buffer Overflows Happen in C with sprintf() and How to Fix Them

A critical stack buffer overflow was discovered in `libuv/Learn-libuv/docs/code/tty-gravity/main.c` where `sprintf()` wrote ANSI escape sequences and user-controlled variables into a fixed 500-byte buffer without any bounds checking. An attacker controlling the `pos`, `width`, or `message` variables could overflow the stack, overwrite return addresses, and potentially achieve arbitrary code execution. The fix replaces `sprintf()` with `snprintf()` and adds explicit length validation to ensure wr

#buffer-overflow#c#memory-safety+3 more
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anupamme
Aug 26, 2026
high7 min

How insecure string copy functions happen in C and how to fix them

A high-severity buffer overflow risk was discovered in `login/main.c` where `strcpy()` was used to copy the `HOME` environment variable into a fixed-size 512-byte buffer without any bounds checking. An attacker controlling the `HOME` environment variable could overflow `pwd_file_name`, potentially corrupting memory or hijacking execution. The fix replaces the two-step `strcpy`/`strcat` pattern with a single, bounds-safe `snprintf` call.

#c#buffer-overflow#strcpy+4 more
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anupamme
Aug 22, 2026
high6 min

How c.lang.security.use-after-free.use-after-free happens in C and how to fix it

A use-after-free vulnerability was discovered in `ggml-alloc.c` where `galloc->leaf_allocs` could be referenced after being freed during graph memory reallocation. The fix nullifies the pointer immediately after `free()` and uses explicit `sizeof(struct leaf_alloc)` to prevent undefined behavior. This defensive hardening eliminates an exploit primitive in a speech-to-text processing pipeline.

#security#use-after-free#c+4 more
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anupamme
Aug 22, 2026
critical9 min

How buffer overflow in Intel SGX enclave ECALLs happens in C and how to fix it

A critical buffer overflow vulnerability was discovered in Intel SGX enclave functions `ecall_encrypt_data` and `ecall_decrypt_data` in `backend/sgx/enclave/enclave.c`. The functions performed memory operations without validating that the provided buffer lengths matched the actual allocated buffer sizes, allowing an attacker controlling the untrusted application to trigger heap corruption within the secure enclave by passing oversized length parameters.

#security#buffer-overflow#intel-sgx+4 more
A
anupamme
Jul 27, 2026
critical8 min

How buffer overflow happens in C SGX enclave memcpy and how to fix it

A critical buffer overflow vulnerability was discovered in `backend/sgx/enclave/enclave.c` where the `ecall_store_data` function performed `memcpy` operations without proper bounds checking against the actual destination buffer size. An attacker could supply a malicious `data_len` parameter to overflow the enclave's secure storage buffer, potentially corrupting trusted execution environment memory. The fix replaces a hardcoded magic number check with a precise size comparison against the actual

#buffer-overflow#c#sgx+4 more
A
anupamme
Jul 26, 2026
medium7 min

How integer underflow in array splice operations happens in C and how to fix it

A critical integer underflow vulnerability was discovered in tree-sitter's array.h header file, where the `_array__splice()` function calculated array sizes without proper bounds checking. The vulnerable code relied on assert() statements that are disabled in release builds, allowing arithmetic underflow when `old_count > *size + new_count`, potentially causing memory corruption through out-of-bounds memcpy operations.

#c#integer-underflow#buffer-overflow+4 more
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anupamme
Jul 25, 2026
high6 min

How buffer overflow via sprintf() happens in C string formatting and how to fix it

A high-severity buffer overflow vulnerability was discovered in `bench/strbuild/strbuild.c` where `sprintf()` wrote formatted output into a 64-byte stack buffer (`line[64]`) without any bounds checking. An attacker who could influence the values in the `NAMES[]`, `c[]`, or `v[]` arrays could overflow this buffer, potentially corrupting the stack and hijacking control flow. The fix replaces `sprintf()` with `snprintf(line, sizeof(line), ...)` to enforce a strict 64-byte write limit.

#security#buffer-overflow#c+4 more
A
anupamme
Jul 23, 2026
critical8 min

How buffer overflow happens in C ieee80211_input() and how to fix it

A critical buffer overflow vulnerability was discovered in `src/firmware/src/net/ieee80211.c` at line 1584, where the `ieee80211_input()` function processed raw 802.11 data frames without verifying that the incoming frame was large enough to contain a valid `ieee80211_frame` header. An attacker within wireless range could craft undersized or malformed frames to trigger memory corruption, potentially leading to remote code execution on the firmware. The fix adds a single, targeted bounds check th

#buffer-overflow#c#firmware+4 more
O
orbisai0security
Jul 13, 2026
critical5 min

How buffer overflow via strcpy() happens in C Kconfig parsing and how to fix it

A critical buffer overflow vulnerability was discovered in the Linux kernel's Kconfig build system where `strcpy()` copied user-controlled symbol values into a fixed-size buffer without bounds checking. This flaw in `scripts/kconfig/symbol.c` could allow attackers to overwrite adjacent memory when processing malicious Kconfig files. The fix replaces the unsafe `strcpy()` with `memcpy()` using explicit length calculations.

#security#buffer-overflow#c+4 more
O
orbisai0security
Jul 11, 2026
high6 min

How integer overflow in malloc happens in C bipartite matching and how to fix it

A high-severity integer overflow vulnerability was discovered in the bipartite matching algorithm implementation where unchecked multiplication operations for memory allocation could wrap around, causing undersized buffer allocations and subsequent heap overflow. The fix replaces vulnerable `malloc(sizeof(int) * V)` patterns with safe `calloc(V, sizeof(int))` calls and adds proper bounds validation to prevent exploitation.

#security#c#integer-overflow+4 more
O
orbisai0security
Jul 10, 2026