The reason behind this one is that without a real variable name, the profile objects are immediately desctructed and the profiling only happens for the small window when they were valid. If the intention is to profile the method where they were defined, this doesn't actually happen.
An attacker can make Zeek crash by posting the KEX packet twice, which
will result in an assertion failure in binpac::datastring::init():
#0 __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50
#1 0x00007ffff5196535 in __GI_abort () at abort.c:79
#2 0x00007ffff519640f in __assert_fail_base (fmt=0x7ffff52f86e0 "%s%s%s:%u: %s%sAssertion `%s' failed.\n%n", assertion=0x1d33530 "!data_",
file=0x1d33537 "aux/binpac/lib/binpac_bytestring.h", line=108, function=<optimized out>) at assert.c:92
#3 0x00007ffff51a3b92 in __GI___assert_fail (assertion=0x1d33530 "!data_", file=0x1d33537 "aux/binpac/lib/binpac_bytestring.h",
line=108, function=0x1d3356c "void binpac::datastring<unsigned char>::init(const T *, int) [T = unsigned char]") at assert.c:101
#4 0x0000000000c1e970 in binpac::datastring<unsigned char>::init (this=0x608000d609d0, begin=0x603001bdd1d0 "diffie-hellman-group16-sha512", length=29)
at aux/binpac/lib/binpac_bytestring.h:108
#5 0x0000000000e9ab60 in binpac::SSH::SSH_Conn::update_kex (this=0x608000d609a0, algs=..., orig=true) at src/analyzer/protocol/ssh/ssh_pac.cc:205
#6 0x0000000000ea0d06 in binpac::SSH::SSH2_KEXINIT::Parse (this=0x60b000734680,
t_begin_of_data=0x621000004753 "\200\275\a%\223\023Y8\204t\235\363!\031I.", t_end_of_data=0x621000004b85 "ޭ\276", <incomplete sequence \357>,
t_context=0x603001bdcc90, t_byteorder=0) at src/analyzer/protocol/ssh/ssh_pac.cc:1598
#7 0x0000000000e9f8f4 in binpac::SSH::SSH2_Message::Parse (this=0x608000d60ea0,
t_begin_of_data=0x621000004753 "\200\275\a%\223\023Y8\204t\235\363!\031I.", t_end_of_data=0x621000004b85 "ޭ\276", <incomplete sequence \357>,
t_context=0x603001bdcc90, t_byteorder=0) at src/analyzer/protocol/ssh/ssh_pac.cc:1326
#8 0x0000000000e9d7e1 in binpac::SSH::SSH2_Key_Exchange::Parse (this=0x604001779850,
t_begin_of_data=0x621000004751 "\006\024\200\275\a%\223\023Y8\204t\235\363!\031I.", t_end_of_data=0x621000004b85 "ޭ\276", <incomplete sequence \357>,
t_context=0x603001bdcc90, t_byteorder=0) at src/analyzer/protocol/ssh/ssh_pac.cc:1210
#9 0x0000000000e9c981 in binpac::SSH::SSH_Key_Exchange::ParseBuffer (this=0x603001bdccc0, t_flow_buffer=0x608000d60a20, t_context=0x603001bdcc90,
t_byteorder=0) at src/analyzer/protocol/ssh/ssh_pac.cc:628
#10 0x0000000000e9c26c in binpac::SSH::SSH_PDU::ParseBuffer (this=0x604001779810, t_flow_buffer=0x608000d60a20, t_context=0x603001bdcc90)
at src/analyzer/protocol/ssh/ssh_pac.cc:446
#11 0x0000000000ea6f04 in binpac::SSH::SSH_Flow::NewData (this=0x604001774690, t_begin_of_data=0x62100000474d "",
t_end_of_data=0x621000004b85 "ޭ\276", <incomplete sequence \357>) at src/analyzer/protocol/ssh/ssh_pac.cc:3071
#12 0x0000000000e9a38f in binpac::SSH::SSH_Conn::NewData (this=0x608000d609a0, is_orig=true, begin=0x62100000474d "",
end=0x621000004b85 "ޭ\276", <incomplete sequence \357>) at src/analyzer/protocol/ssh/ssh_pac.cc:63
#13 0x0000000000e98335 in analyzer::SSH::SSH_Analyzer::DeliverStream (this=0x7fffffffdd40, len=1080, data=0x62100000474d "", orig=true)
at src/analyzer/protocol/ssh/SSH.cc:68
With assertions turned off, this would "only" be a memory leak.
This commit fixes the vulnerability by freeing and clearing the
`binpac::datastring` before assigning a new value.
* max/optimize:
plugin/Manager: migrate to std::string_view
util: optimize the normal_path() common case
util: pass string_view to without_bropath_component()
module_util: make GLOBAL_MODULE_NAME constexpr
Scope: convert Scope::Lookup() and others to template
Scope: Vars() returns const reference
Anon: remove unnecessary {map,vector}::clear() calls
Dict: make the destructor non-virtual
Obj: make the Location constructors `constexpr`
Obj: remove unused fields Location::{timestamp,text}
Obj: remove Location::delete_data, nobody ever sets it
Obj: make the Location destructor non-virtual
* origin/topic/johanna/table-on-change:
&on_change: Address feedback of Jon.
&on_change: incooperate feedback of Jon.
&on_change wrapup: documentation, tests, whitespacing
Table expiry now raises &on_change handlers
Prevent recursion of &on_change handlers.
Make bro_broker::val_to_data take a const Val* instead of a Val
&on_change: add insertion/change notifications.
&on_change working for removals from tables.
Change signature of &on_change handler
Beginning implementation of &on_change for tables.
