CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
NONE
Availability Impact
NONE
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
AI Score
Confidence
High
EPSS
Percentile
10.3%
In the Linux kernel, the following vulnerability has been resolved: binder:
fix async_free_space accounting for empty parcels In 4.13, commit
74310e06be4d (“android: binder: Move buffer out of area shared with user
space”) fixed a kernel structure visibility issue. As part of that patch,
sizeof(void *) was used as the buffer size for 0-length data payloads so
the driver could detect abusive clients sending 0-length asynchronous
transactions to a server by enforcing limits on async_free_size.
Unfortunately, on the “free” side, the accounting of async_free_space did
not add the sizeof(void *) back. The result was that up to 8-bytes of
async_free_space were leaked on every async transaction of 8-bytes or less.
These small transactions are uncommon, so this accounting issue has gone
undetected for several years. The fix is to use “buffer_size” (the
allocated buffer size) instead of “size” (the logical buffer size) when
updating the async_free_space during the free operation. These are the same
except for this corner case of asynchronous transactions with payloads < 8
bytes.
OS | Version | Architecture | Package | Version | Filename |
---|---|---|---|---|---|
ubuntu | 18.04 | noarch | linux | < any | UNKNOWN |
ubuntu | 20.04 | noarch | linux | < 5.4.0-105.119 | UNKNOWN |
ubuntu | 18.04 | noarch | linux-aws | < any | UNKNOWN |
ubuntu | 20.04 | noarch | linux-aws | < 5.4.0-1069.73 | UNKNOWN |
ubuntu | 18.04 | noarch | linux-aws-5.4 | < any | UNKNOWN |
ubuntu | 16.04 | noarch | linux-aws-hwe | < 4.15.0-1124.133~16.04.1 | UNKNOWN |
ubuntu | 20.04 | noarch | linux-azure | < 5.4.0-1073.76 | UNKNOWN |
ubuntu | 14.04 | noarch | linux-azure | < 4.15.0-1134.147~14.04.1 | UNKNOWN |
ubuntu | 16.04 | noarch | linux-azure | < 4.15.0-1134.147~16.04.1 | UNKNOWN |
ubuntu | 18.04 | noarch | linux-azure-4.15 | < any | UNKNOWN |
git.kernel.org/linus/cfd0d84ba28c18b531648c9d4a35ecca89ad9901 (5.16-rc8)
git.kernel.org/stable/c/103b16a8c51f96d5fe063022869ea906c256e5da
git.kernel.org/stable/c/17691bada6b2f1d5f1c0f6d28cd9d0727023b0ff
git.kernel.org/stable/c/1cb8444f3114f0bb2f6e3bcadcf09aa4a28425d4
git.kernel.org/stable/c/2d2df539d05205fd83c404d5f2dff48d36f9b495
git.kernel.org/stable/c/7c7064402609aeb6fb11be1b4ec10673ff17b593
git.kernel.org/stable/c/cfd0d84ba28c18b531648c9d4a35ecca89ad9901
launchpad.net/bugs/cve/CVE-2021-46935
nvd.nist.gov/vuln/detail/CVE-2021-46935
security-tracker.debian.org/tracker/CVE-2021-46935
www.cve.org/CVERecord?id=CVE-2021-46935