Summary
Package updates are available for Amazon Linux 2 that fix the following vulnerabilities: CVE-2021-3782: An internal reference count is held on the buffer pool, incremented every time a new buffer is created from the pool. The reference count is maintained as an int; on LP64 systems this can cause the reference count to overflow if the client creates a large number of wl_shm buffer objects, or if it can coerce the server to create a large number of external references to the buffer storage. With the reference count overflowing, a use-after-free can be constructed on the wl_shm_pool tracking structure, where values may be incremented or decremented; it may also be possible to construct a limited oracle to leak 4 bytes of server-side memory to the attacking client at a time.
Fixed packages 7
| Release | Package | Fixed in |
|---|---|---|
| Amazon Linux · 2 | libwayland-client | 0:1.17.0-1.amzn2.0.1 |
| Amazon Linux · 2 | libwayland-cursor | 0:1.17.0-1.amzn2.0.1 |
| Amazon Linux · 2 | libwayland-egl | 0:1.17.0-1.amzn2.0.1 |
| Amazon Linux · 2 | libwayland-server | 0:1.17.0-1.amzn2.0.1 |
| Amazon Linux · 2 | wayland-debuginfo | 0:1.17.0-1.amzn2.0.1 |
| Amazon Linux · 2 | wayland-devel | 0:1.17.0-1.amzn2.0.1 |
| Amazon Linux · 2 | wayland-doc | 0:1.17.0-1.amzn2.0.1 |
Vulnerabilities 1
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Medium 6.6
An internal reference count is held on the buffer pool, incremented every time a new buffer is created from the pool. T…
References
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web
https://alas.aws.amazon.com/cve/html/CVE-2021-3782.html