In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
staging: rtl8723bs: fix OOB read \/ stack overflow in rtw_get_wps_attr()<\/p>\n
rtw_get_wps_attr() walks WPS attributes inside a WPS IE taken from
\na wireless management frame. For each candidate attribute it only
\nchecks that the fixed 4-byte attribute header (2-byte ID + 2-byte
\nlength) fits inside the IE:<\/p>\n
\tif (attr_ptr + 4 > wps_ie + wps_ielen)
\n\t\tbreak;
\n\tu16 attr_id = get_unaligned_be16(attr_ptr);
\n\tu16 attr_data_len = get_unaligned_be16(attr_ptr + 2);
\n\tu16 attr_len = attr_data_len + 4;<\/p>\n
attr_data_len (and therefore attr_len) is read directly from the
\nwire and is never checked against the remaining bytes in the IE
\nbefore being used as the size of:<\/p>\n
\tmemcpy(buf_attr, attr_ptr, attr_len);<\/p>\n
Since attr_len is fully attacker controlled (0 to 65535+4), this is
\nboth a heap OOB read of wps_ie, and, more seriously, a stack buffer
\noverflow at several call sites where buf_attr is a single-byte
\nstack variable, e.g. rtw_get_wps_attr_content()’s callers passing
\nWPS_ATTR_SELECTED_REGISTRAR into a stack “u8 sr”\/”u8
\nselected_registrar” (drivers\/staging\/rtl8723bs\/os_dep\/ioctl_cfg80211.c,
\ndrivers\/staging\/rtl8723bs\/core\/rtw_mlme_ext.c). A crafted WPS IE in a
\nbeacon or probe response processed during scanning can therefore
\nsmash the stack of the parsing thread.<\/p>\n
rtw_get_wps_attr_content() itself has no independent length check
\nand simply trusts the attr_len it gets back from rtw_get_wps_attr(),
\nso fixing the bound here also fixes that caller.<\/p>\n
The “attr_ptr + 4 > wps_ie + wps_ielen” header check above was added
\nby commit 1463ca3ec6601 (“staging: rtl8723bs: fix OOB reads in
\nrtw_get_sec_ie(), rtw_get_wapi_ie(), and rtw_get_wps_attr()”), which
\nbounded the fixed header but never extended the check to cover the
\nvariable-length attribute data that follows it. Add that missing
\ncheck before attr_len is used as a memcpy() length or accepted as a
\nmatch.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
staging: rtl8723bs: fix OOB read \/ stack overflow in rtw_get_wps_attr()<\/p>\n
rtw_get_wps_attr() walks WPS attributes inside a WPS IE ta<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-24706","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/24706","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln"}],"about":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/types\/vuln"}],"wp:attachment":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=24706"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=24706"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=24706"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}