CVE-2022-24795: brianmario yajl-ruby Heap-based Buffer Overflow

Vulnerability summary

CVE-2022-24795 is a high (CVSS 7.5) Heap-based Buffer Overflow vulnerability in brianmario yajl-ruby. EPSS estimates a 3.47% chance of exploitation in the next 30 days, higher than 88.9% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 05-04-2022
   PublishedVulnerability first disclosed.
2. 22-04-2025
   Last modifiedVulnerability information updated.

Description

yajl-ruby is a C binding to the YAJL JSON parsing and generation library. The 1.x branch and the 2.x branch of `yajl` contain an integer overflow which leads to subsequent heap memory corruption when dealing with large (~2GB) inputs. The reallocation logic at `yajl_buf.c#L64` may result in the `need` 32bit integer wrapping to 0 when `need` approaches a value of 0x80000000 (i.e. ~2GB of data), which results in a reallocation of buf->alloc into a small heap chunk. These integers are declared as `size_t` in the 2.x branch of `yajl`, which practically prevents the issue from triggering on 64bit platforms, however this does not preclude this issue triggering on 32bit builds on which `size_t` is a 32bit integer. Subsequent population of this under-allocated heap chunk is based on the original buffer size, leading to heap memory corruption. This vulnerability mostly impacts process availability. Maintainers believe exploitation for arbitrary code execution is unlikely. A patch is available and anticipated to be part of yajl-ruby version 1.4.2. As a workaround, avoid passing large inputs to YAJL.

• CWE-122Heap-based Buffer OverflowA heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().
• CWE-190Integer Overflow or WraparoundThe product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.