As announced by Go upstream on 2019-10-17: Invalid DSA public keys can cause a panic in dsa.Verify. In particular, using crypto/x509.Verify on a crafted X.509 certificate chain can lead to a panic, even if the certificates don’t chain to a trusted root. The chain can be delivered via a crypto/tls connection to a client, or to a server that accepts and verifies client certificates. net/http clients can be made to crash by an HTTPS server, while net/http servers that accept client certificates will recover the panic and are unaffected.
Moreover, an application might crash invoking crypto/x509.(CertificateRequest) CheckSignature on an X.509 certificate request, parsing a golang.org/x/crypto/openpgp Entity, or during a golang.org/x/crypto/otr conversation. Finally, a golang.org/x/crypto/ssh client can panic due to a malformed host key, while a server could panic if either PublicKeyCallback accepts a malformed public key, or if IsUserAuthority accepts a certificate with a malformed public key.
Upstream bug: https://github.com/golang/go/issues/34960
A security regression (CVE-2006-5051) was discovered in OpenSSH's server (sshd). There is a race condition which can lead sshd to handle some signals in an unsafe manner. An unauthenticated, remote attacker may be able to trigger it by failing to authenticate within a set time period.
A flaw was found in the bash functionality that evaluates specially formatted environment variables passed to it from another environment. An attacker could use this feature to override or bypass restrictions to the environment to execute shell commands before restrictions have been applied. Certain services and applications allow remote unauthenticated attackers to provide environment variables, allowing them to exploit this issue.
Acknowledgements:
Red Hat would like to thank Stephane Chazelas for reporting this issue.
In Arista’s EOS when in 802.1X mode, multi-auth unauthenticated hosts might be allowed access to a switch port if there exists an EAPOL capable device in the fallback VLAN.
Affected platforms running Arista EOS with OpenConfig configured, a gNMI Set request can be run when it should have been rejected. This can result in unexpected configuration being applied to the switch.
Arista Extensible Operating System (EOS) contains an incomplete comparison with missing factors vulnerability when the switch incorrectly decapsulate and forwards other unexpected tunneled packet with a destination IP matching its configured decapsulation IP.
Last updated 4 July 2026
GNU Bash through 4.3 bash43-025 processes trailing strings after certain malformed function definitions in the values of environment variables, which allows remote attackers to write to files or possibly have unknown other impact via a crafted environment, as demonstrated by vectors involving the ForceCommand feature in OpenSSH sshd, the modcgi and modcgid modules in the Apache HTTP Server, scripts executed by unspecified DHCP clients, and other situations in which setting the environment occurs across a privilege boundary from Bash execution. NOTE: this vulnerability exists because of an incomplete fix for CVE-2014-6271.
This advisory documents the impact of an internally found vulnerability in Arista EOS for security ACL bypass. The impact of this vulnerability is that the security ACL drop rule might be bypassed if a NAT ACL rule filter with permit action matches the packet flow. This could allow a host with an IP address in a range that matches the range allowed by a NAT ACL and a range denied by a Security ACL to be forwarded incorrectly as it should have been denied by the Security ACL. This can enable an ACL bypass.
utility.c in telnetd in netkit telnet through 0.17 allows remote attackers to execute arbitrary code via short writes or urgent data, because of a buffer overflow involving the netclear and nextitem functions.
On affected platforms running Arista EOS with MACsec configuration, a specially crafted packet can cause the MACsec process to terminate unexpectedly. Continuous receipt of these packets with certain MACsec configurations can cause longer term disruption of dataplane traffic.
On affected platforms running Arista EOS with OSPFv3 configured, a specially crafted packet can cause the OSFPv3 process to have high CPU utilization which may result in the OSFPv3 process being restarted. This may cause disruption in the OSFPv3 routes on the switch.
This issue was discovered internally by Arista and is not aware of any malicious uses of this issue in customer networks.
On affected platforms running Arista EOS, certain serial console input might result in an unexpected reload of the device.153
A flaw was found in dnsmasq before version 2.83. When receiving a query, dnsmasq does not check for an existing pending request for the same name and forwards a new request. By default, a maximum of 150 pending queries can be sent to upstream servers, so there can be at most 150 queries for the same name. This flaw allows an off-path attacker on the network to substantially reduce the number of attempts that it would have to perform to forge a reply and have it accepted by dnsmasq. This issue is mentioned in the "Birthday Attacks" section of RFC5452. If chained with CVE-2020-25684, the attack complexity of a successful attack is reduced. The highest threat from this vulnerability is to data integrity.
A flaw was found in dnsmasq before version 2.83. When getting a reply from a forwarded query, dnsmasq checks in forward.c:replyquery(), which is the forwarded query that matches the reply, by only using a weak hash of the query name. Due to the weak hash (CRC32 when dnsmasq is compiled without DNSSEC, SHA-1 when it is) this flaw allows an off-path attacker to find several different domains all having the same hash, substantially reducing the number of attempts they would have to perform to forge a reply and get it accepted by dnsmasq. This is in contrast with RFC5452, which specifies that the query name is one of the attributes of a query that must be used to match a reply. This flaw could be abused to perform a DNS Cache Poisoning attack. If chained with CVE-2020-25684 the attack complexity of a successful attack is reduced. The highest threat from this vulnerability is to data integrity.
A flaw was found in dnsmasq before version 2.83. When getting a reply from a forwarded query, dnsmasq checks in the forward.c:replyquery() if the reply destination address/port is used by the pending forwarded queries. However, it does not use the address/port to retrieve the exact forwarded query, substantially reducing the number of attempts an attacker on the network would have to perform to forge a reply and get it accepted by dnsmasq. This issue contrasts with RFC5452, which specifies a query's attributes that all must be used to match a reply. This flaw allows an attacker to perform a DNS Cache Poisoning attack. If chained with CVE-2020-25685 or CVE-2020-25686, the attack complexity of a successful attack is reduced. The highest threat from this vulnerability is to data integrity.
On affected platforms running Arista EOS with Traffic Policies configured the vulnerability will cause received untagged packets not to hit Traffic Policy rules that they are expected to hit. If the rule was to drop the packet, the packet will not be dropped and instead will be forwarded as if the rule was not in place. This could lead to packets being delivered to unexpected destinations.
On affected platforms with hardware IPSec support running Arista EOS with IPsec enabled and anti-replay protection configured, EOS may exhibit unexpected behavior in specific cases. Received duplicate encrypted packets, which should be dropped under normal anti-replay protection, will instead be forwarded due to this vulnerability.
Note: this issue does not affect VXLANSec or MACSec encryption functionality.
On affected platforms running Arista EOS, ingress traffic on Layer 2 ports may, under certain conditions, be improperly forwarded to ports associated with different VLANs, resulting in a breach of VLAN isolation and segmentation boundaries.
n affected platforms running Arista EOS, ACL policies may not be enforced. IPv4 ingress ACL, MAC ingress ACL, or IPv6 standard ingress ACL enabled on one or more ethernet or LAG interfaces may result in ACL policies not being enforced for ingress packets. This can cause incoming packets to incorrectly be allowed or denied. The two symptoms of this issue on the affected release and platform are:
Packets which should be permitted may be dropped and, Packets which should be dropped may be permitted.
On affected platforms running Arista EOS with secure Vxlan configured, restarting the Tunnelsec agent will result in packets being sent over the secure Vxlan tunnels in the clear.
On affected platforms running Arista EOS with a gNMI transport enabled, running the gNOI File TransferToRemote RPC with credentials for a remote server may cause these remote-server credentials to be logged or accounted on the local EOS device or possibly on other remote accounting servers (i.e. TACACS, RADIUS, etc).
For certain systems running EOS, a Precision Time Protocol (PTP) packet of a management/signaling message with an invalid Type-Length-Value (TLV) causes the PTP agent to restart. Repeated restarts of the service will make the service unavailable.
On affected platforms running Arista EOS with BGP Link State configured, BGP peer flap can cause the BGP agent to leak memory. This may result in BGP routing processing being terminated and route flapping.
On affected platforms running Arista EOS with 802.1X configured, certain conditions may occur where a dynamic ACL is received from the AAA server resulting in only the first line of the ACL being installed after an Accelerated Software Upgrade (ASU) restart.
Note: supplicants with pending captive-portal authentication during ASU would be impacted with this bug.
On affected platforms running Arista EOS with OpenConfig configured, a gNOI request can be run when it should have been rejected. This issue can result in unexpected configuration/operations being applied to the switch.
On affected platforms running Arista EOS with OpenConfig configured, a gNOI request can be run when it should have been rejected. This issue can result in users retrieving data that should not have been available
On affected platforms running Arista EOS with SNMP configured, a specially crafted packet can cause a memory leak in the snmpd process. This may result in the snmpd processing being terminated (causing SNMP requests to time out until snmpd is automatically restarted) and potential memory resource exhaustion for other processes on the switch. The vulnerability does not have any confidentiality or integrity impacts to the system.
On affected modular platforms running Arista EOS equipped with both redundant supervisor modules and having the redundancy protocol configured with RPR or SSO, an existing unprivileged user can login to the standby supervisor as a root user, leading to a privilege escalation. Valid user credentials are required in order to exploit this vulnerability.
Heap-based buffer overflow in dnsmasq before 2.78 allows remote attackers to cause a denial of service (crash) or execute arbitrary code via a crafted DNS response.