| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| Buffer over-read in Microsoft Office PowerPoint allows an unauthorized attacker to disclose information over a network. |
| In the Linux kernel, the following vulnerability has been resolved:
net: always dissect GSO packets in __virtio_net_hdr_to_skb()
Commit 9e8db5913264 ("net: avoid false positives in untrusted gso
validation") added a '&& skb->network_header' check before flow-dissecting
GSO packets without VIRTIO_NET_HDR_F_NEEDS_CSUM in
__virtio_net_hdr_to_skb(), because some callers (such as tun_get_user(),
tun_xdp_one(), virtnet_receive_done(), and raw_verify_header()) called
virtio_net_hdr_*_to_skb() before initializing skb->network_header and
skb->dev.
Because __alloc_skb() and __build_skb_around() zero-initialize
skb->network_header to 0 (unlike mac_header and transport_header which
are initialized to ~0U), those four callers always had
skb->network_header == 0 and bypassed flow dissection in
__virtio_net_hdr_to_skb(). More generally, skb->network_header is an
offset from skb->head (where 0 is also a valid offset whenever
skb_headroom(skb) is 0), not a boolean flag.
Whenever the 'if (gso_type && skb->network_header)' branch was skipped,
the fallback 'else if (gso_type)' only pulled nh_min_len + thlen (40 bytes
for TCPv4) without dissecting the packet, without validating ip_proto or
n_proto, and without setting skb->transport_header.
If the packet has a malformed network header, it is not rejected and a
subsequent skb_probe_transport_header() also fails, leaving
skb->transport_header at ~0U (0xffff). Similarly, if an IPv4 packet
carries IP options (ihl > 5) or an IPv6 packet carries extension headers,
pulling only nh_min_len + thlen can leave the TCP header outside
skb->head. In both cases, tcp_hdrlen(skb) in skb_gso_transport_seglen()
reads out-of-bounds:
BUG: KASAN: slab-out-of-bounds in skb_gso_transport_seglen
Read of size 2 by task poc/133
skb_gso_transport_seglen (net/core/gso.c:155)
skb_gso_validate_mac_len (net/core/gso.c:270)
tbf_enqueue (net/sched/sch_tbf.c:260)
dev_qdisc_enqueue (net/core/dev.c:4227)
__dev_queue_xmit (net/core/dev.c:4884)
In addition, checking virtio_net_hdr_match_proto() only inside
'if (!skb->protocol)' before flow dissection both skipped validation when
skb->protocol was pre-set by the caller and rejected VLAN-tagged frames
whose outer L2 protocol is ETH_P_8021Q or ETH_P_8021AD.
Fix this by:
1. Initializing skb->dev and skb->network_header (plus skb->protocol for
IFF_TUN) before virtio_net_hdr_*_to_skb() in tun_get_user(),
tun_xdp_one(), virtnet_receive_done(), and raw_verify_header(). In
tun_get_user(), drop the redundant skb_reset_mac_header(skb) in the
IFF_TUN case since __virtio_net_hdr_to_skb() unconditionally resets
mac_header.
2. Removing '&& skb->network_header' and the unvalidated
'else if (gso_type)' fallback in __virtio_net_hdr_to_skb() so all GSO
packets without VIRTIO_NET_HDR_F_NEEDS_CSUM are flow-dissected, have
their transport header pulled into linear data, and have
skb->transport_header set.
3. Moving the virtio_net_hdr_match_proto() check to after
skb_flow_dissect_flow_keys_basic(), validating keys.basic.n_proto
against hdr_gso_type. |
| In the Linux kernel, the following vulnerability has been resolved:
flow_dissector: avoid u16 truncation of skb->len when computing thoff
__skb_flow_dissect() computes key_control->thoff using:
key_control->thoff = min_t(u16, nhoff, skb ? skb->len : hlen);
min_t(u16, ...) casts both arguments to u16 before comparing them.
Whenever skb->len (or hlen) modulo 65536 is smaller than nhoff, the
truncated length wins and thoff is set to a bogus small value, even
when the dissection succeeded. For example, an IPv4/TCP frame with
skb->len == 65540 and nhoff == 34 gets thoff == 4, so callers such as
skb_probe_transport_header() point the transport header inside the
Ethernet header.
Such skbs are not exotic:
- At the time of commit d0c081b49137 ("flow_dissector: properly cap
thoff field"), AF_PACKET with PACKET_VNET_HDR could already build GSO
skbs larger than 64KB (MTU checks are skipped for GSO, and
alloc_skb_with_frags() accepted up to MAX_SKB_FRAGS (17) order-0
pages on top of the linear part).
- BIG TCP now makes skbs larger than 64KB common.
- The following patch makes tun_get_user() dissect IFF_TAP frames
before eth_type_trans() pulls the Ethernet header, so a GSO frame
carrying a 65522..65535 byte L3 packet will be dissected with
skb->len in [65536, 65549].
Compare as u32 instead. If the resulting offset cannot be represented
in the u16 key_control->thoff, cap it to U16_MAX and report the
dissection as failed rather than silently returning a wrong transport
offset. thoff is still set on failure, as some callers (such as
eth_get_headlen()) use it regardless of the return value. |
| Out-of-bounds read in Windows Key Storage Provider allows an authorized attacker to disclose information locally. |
| Heap-based buffer overflow in Windows kernel32.dll allows an authorized attacker to elevate privileges locally. |
| Heap-based buffer overflow in Graphic Fonts allows an unauthorized attacker to execute code over a network. |
| Heap-based buffer overflow in Windows Error Reporting allows an authorized attacker to elevate privileges locally. |
| Heap-based buffer overflow in Windows Error Reporting allows an authorized attacker to elevate privileges over a network. |
| Heap-based buffer overflow in Microsoft PostScript Printer Driver allows an unauthorized attacker to elevate privileges locally. |
| Stack-based buffer overflow in Windows Internet Information Services allows an unauthorized attacker to execute code over a network. |
| Integer overflow or wraparound in Windows IP Over USB Service allows an authorized attacker to elevate privileges locally. |
| Weak authentication in Active Directory Federation Services (AD FS) allows an unauthorized attacker to bypass a security feature over a network. |
| Heap-based buffer overflow in Windows Storage Spaces Controller allows an authorized attacker to elevate privileges locally. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211_hwsim: reject undersized HWSIM_ATTR_TX_INFO
hwsim_tx_info_frame_received_nl() casts the HWSIM_ATTR_TX_INFO payload
to a struct hwsim_tx_rate * and unconditionally reads
IEEE80211_TX_MAX_RATES entries (8 bytes) from it. The policy only bounds
the attribute from above (NLA_BINARY .len is a maximum) and the op sets
GENL_DONT_VALIDATE_STRICT, so a short or zero-length attribute is
accepted and the loop reads past the payload.
Require the exact length in the policy, so a malformed attribute is
rejected before the handler runs. |
| Integer overflow or wraparound in Windows iSCSI allows an unauthorized attacker to execute code over a network. |
| Stack-based buffer overflow in Windows Installer allows an authorized attacker to elevate privileges locally. |
| Out-of-bounds read in Microsoft Digest Authentication allows an authorized attacker to disclose information locally. |
| Out-of-bounds read in DNS Server allows an unauthorized attacker to disclose information over a network. |
| Heap-based buffer overflow in Windows Remote Access Connection Manager allows an authorized attacker to elevate privileges locally. |
| Heap-based buffer overflow in Windows Volume Manager Extension Driver allows an unauthorized attacker to execute code over a network. |
