Headline
CVE-2022-24795: Build software better, together
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.
Package
Affected versions
<= 1.4.1
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 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.
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 1.4.2
Workarounds
Avoid passing large inputs to YAJL
References
while (want >= (need - buf->used)) need <<= 1;
For more information
If you have any questions or comments about this advisory:
- Open an issue in yajl-ruby
CVE ID
CVE-2022-24795
GHSA ID
GHSA-jj47-x69x-mxrm
CWEs
CVSS Score
5.9 Moderate
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
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**Why is Attack Complexity marked as High for this vulnerability?** Successful exploitation of this vulnerability requires an attacker to win a race condition.
**I am running a supported version of Windows Server. Is my system vulnerable to this issue?** This vulnerability is only exploitable for systems that have the NFS role enabled. See NFS Overview for more information on this feature. More information on installing or uninstalling Roles or Role Services is available here.