CVE-2022-24795: Buffer Overflow and Integer Overflow in yajl-ruby
NOTE: A previous patch, 1.4.2, fixed the heap memory issue, but could still lead to a DoS infinite loop. Please update to version 1.4.3
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.
Details
The reallocation logic at yajlbuf.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 sizet 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 sizet is a 32bit integer.
Subsequent population of this under-allocated heap chunk is based on the original buffer size, leading to heap memory corruption.
Impact
We rate this as a moderate severity vulnerability which mostly impacts process availability as we believe exploitation for arbitrary code execution to be unlikely.
Patches
Patched in yajl-ruby 1.4.3
Workarounds
Avoid passing large inputs to YAJL
References https://github.com/brianmario/yajl-ruby/blob/7168bd79b888900aa94523301126f968a93eb3a6/ext/yajl/yajlbuf.c#L64
For more information If you have any questions or comments about this advisory: Open an issue in yajl-ruby
Other sources
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 yajlbuf.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 sizet 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 sizet 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.
— Ubuntu
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2022-24795?
The severity of CVE-2022-24795 is considered moderate due to potential denial-of-service impacts.
How do I fix CVE-2022-24795?
To fix CVE-2022-24795, update to yajl-ruby version 1.4.3 or higher.
Which versions of yajl are affected by CVE-2022-24795?
Versions up to and including 1.4.2 of yajl are affected by CVE-2022-24795.
What types of systems are impacted by CVE-2022-24795?
CVE-2022-24795 impacts systems using the yajl-ruby package prior to version 1.4.3.
Can CVE-2022-24795 lead to any data loss?
CVE-2022-24795 primarily leads to denial-of-service but does not result in data loss.