A malicious server can crash the OpenAFS cache manager and other client utilities, and possibly execute arbitrary code.

An authenticated user can provide a malformed ACL to the fileserver's StoreACL RPC, causing the fileserver to crash, possibly expose uninitialized memory, and possibly store garbage data in the audit log. Malformed ACLs provided in responses to client FetchACL RPCs can cause client processes to crash and possibly expose uninitialized memory into other ACLs stored on the server.

A local user can bypass the OpenAFS PAG (Process Authentication Group) throttling mechanism in Unix clients, allowing the user to create a PAG using an existing id number, effectively joining the PAG and letting the user steal the credentials in that PAG.

In the Linux kernel, the following vulnerability has been resolved:

afs: Fix corruption in reads at fpos 2G-4G from an OpenAFS server

AFS-3 has two data fetch RPC variants, FS.FetchData and FS.FetchData64, and Linux's afs client switches between them when talking to a non-YFS server if the read size, the file position or the sum of the two have the upper 32 bits set of the 64-bit value.

This is a problem, however, since the file position and length fields of FS.FetchData are signed 32-bit values.

Fix this by capturing the capability bits obtained from the fileserver when it's sent an FS.GetCapabilities RPC, rather than just discarding them, and then picking out the VICEDCAPABILITY64BITFILES flag. This can then be used to decide whether to use FS.FetchData or FS.FetchData64 - and also FS.StoreData or FS.StoreData64 - rather than using upper32bits() to switch on the parameter values.

This capabilities flag could also be used to limit the maximum size of the file, but all servers must be checked for that.

Note that the issue does not exist with FS.StoreData - that uses unsigned 32-bit values. It's also not a problem with Auristor servers as its YFS.FetchData64 op uses unsigned 64-bit values.

This can be tested by cloning a git repo through an OpenAFS client to an OpenAFS server and then doing "git status" on it from a Linux afs client[1]. Provided the clone has a pack file that's in the 2G-4G range, the git status will show errors like:

error: packfile .git/objects/pack/pack-5e813c51d12b6847bbc0fcd97c2bca66da50079c.pack does not match index error: packfile .git/objects/pack/pack-5e813c51d12b6847bbc0fcd97c2bca66da50079c.pack does not match index

This can be observed in the server's FileLog with something like the following appearing:

Sun Aug 29 19:31:39 2021 SRXAFSFetchData, Fid = 2303380852.491776.3263114, Host 192.168.11.201:7001, Id 1001 Sun Aug 29 19:31:39 2021 CheckRights: len=0, for host=192.168.11.201:7001 Sun Aug 29 19:31:39 2021 FetchDataRXStyle: Pos 18446744071815340032, Len 3154 Sun Aug 29 19:31:39 2021 FetchDataRXStyle: file size 2400758866 ... Sun Aug 29 19:31:40 2021 SRXAFSFetchData returns 5

Note the file position of 18446744071815340032. This is the requested file position sign-extended.

OpenAFS before 1.6.24 and 1.8.x before 1.8.5 is prone to an information disclosure vulnerability because uninitialized scalars are sent over the network to a peer.

OpenAFS before 1.6.24 and 1.8.x before 1.8.5 is prone to information leakage upon certain error conditions because uninitialized RPC output variables are sent over the network to a peer.

OpenAFS before 1.6.24 and 1.8.x before 1.8.5 is prone to denial of service from unserialized data access because remote attackers can make a series of VOTEDebug RPC calls to crash a database server within the SVOTEDebug RPC handler.

An issue was discovered in OpenAFS before 1.6.23 and 1.8.x before 1.8.2. Several data types used as RPC input variables were implemented as unbounded array types, limited only by the inherent 32-bit length field to 4 GB. An unauthenticated attacker could send, or claim to send, large input values and consume server resources waiting for those inputs, denying service to other valid connections.

An issue was discovered in OpenAFS before 1.6.23 and 1.8.x before 1.8.2. Several RPC server routines did not fully initialize their output variables before returning, leaking memory contents from both the stack and the heap. Because the OpenAFS cache manager functions as an Rx server for the AFSCB service, clients are also susceptible to information leakage. For example, RXAFSCBTellMeAboutYourself leaks kernel memory and KAMListEntry leaks kaserver memory.

An issue was discovered in OpenAFS before 1.6.23 and 1.8.x before 1.8.2. The backup tape controller (butc) process accepts incoming RPCs but does not require (or allow for) authentication of those RPCs. Handling those RPCs results in operations being performed with administrator credentials, including dumping/restoring volume contents and manipulating the backup database. For example, an unauthenticated attacker can replace any volume's content with arbitrary data.

OpenAFS 1.x before 1.6.22 does not properly validate Rx ack packets, which allows remote attackers to cause a denial of service (system crash or application crash) via crafted fields, as demonstrated by an integer underflow and assertion failure for a small MTU value.

OpenAFS 1.6.19 and earlier allows remote attackers to obtain sensitive directory information via vectors involving the (1) client cache partition, (2) fileserver vice partition, or (3) certain RPC responses.

The newEntry function in ptserver/ptprocs.c in OpenAFS before 1.6.17 allows remote authenticated users from foreign Kerberos realms to bypass intended access restrictions and create arbitrary groups as administrators by leveraging mishandling of the creator ID.

Off-by-one error in afspioctl.c in OpenAFS before 1.6.16 might allow local users to cause a denial of service (memory overwrite and system crash) via a pioctl with an input buffer size of 4096 bytes.

The client in OpenAFS before 1.6.17 does not properly initialize the (1) AFSStoreStatus, (2) AFSStoreVolumeStatus, (3) VldbListByAttributes, and (4) ListAddrByAttributes structures, which might allow remote attackers to obtain sensitive memory information by leveraging access to RPC call traffic.

rx/rx.c in OpenAFS before 1.6.15 and 1.7.x before 1.7.33 does not properly initialize the padding of a data structure when constructing an Rx acknowledgement (ACK) packet, which allows remote attackers to obtain sensitive information by (1) conducting a replay attack or (2) sniffing the network.

rx/rx.c in OpenAFS 1.5.75 through 1.5.78, 1.6.x before 1.6.15, and 1.7.x before 1.7.33 does not properly initialize padding at the end of an Rx acknowledgement (ACK) packet, which allows remote attackers to obtain sensitive information by (1) conducting a replay attack or (2) sniffing the network.

The vlserver in OpenAFS before 1.6.13 allows remote authenticated users to cause a denial of service (out-of-bounds read and crash) via a crafted regular expression in a VLListAttributesN2 RPC.

Buffer overflow in the Solaris kernel extension in OpenAFS before 1.6.13 allows local users to cause a denial of service (panic or deadlock) or possibly have other unspecified impact via a large group list when joining a PAG.

OpenAFS before 1.6.13 allows remote attackers to spoof bos commands via unspecified vectors.

The pioctl for the OSD FS command in OpenAFS before 1.6.13 uses the wrong pointer when writing the results of the RPC, which allows local users to cause a denial of service (memory corruption and kernel panic) via a crafted OSD FS command.

vos in OpenAFS before 1.6.13, when updating VLDB entries, allows remote attackers to obtain stack data by sniffing the network.

pioctls in OpenAFS 1.6.x before 1.6.13 allows local users to read kernel memory via crafted commands.

OpenAFS 1.6.8 does not properly clear the fields in the host structure, which allows remote attackers to cause a denial of service (uninitialized memory access and crash) via unspecified vectors related to TMAY requests.

Buffer overflow in the GetStatistics64 remote procedure call (RPC) in OpenAFS 1.4.8 before 1.6.7 allows remote attackers to cause a denial of service (crash) via a crafted statsVersion argument.

OpenAFS before 1.6.7 delays the listen thread when an RXSCheckResponse fails, which allows remote attackers to cause a denial of service (performance degradation) via an invalid packet.

The vos command in OpenAFS 1.6.x before 1.6.5, when using the -encrypt option, only enables integrity protection and sends data in cleartext, which allows remote attackers to obtain sensitive information by sniffing the network.

OpenAFS before 1.4.15, 1.6.x before 1.6.5, and 1.7.x before 1.7.26 uses weak encryption (DES) for Kerberos keys, which makes it easier for remote attackers to obtain the service key.

Integer overflow in ptserver in OpenAFS before 1.6.2 allows remote attackers to cause a denial of service (crash) via a large list from the IdToName RPC, which triggers a heap-based buffer overflow.

Buffer overflow in certain client utilities in OpenAFS before 1.6.2 allows remote authenticated users to cause a denial of service (crash) and possibly execute arbitrary code via a long fileserver ACL entry.