Fix error-prone SQL queries in Account search

While this code seems to not present an actual vulnerability, one could
easily be introduced by mistake due to how the query is built.

This PR parameterises the `to_tsquery` input to make the query more robust.
This commit is contained in:
Claire 2021-03-03 15:08:53 +01:00
parent 3dc0357d9e
commit 2ae33ce39c

View File

@ -428,6 +428,9 @@ class Account < ApplicationRecord
end
class << self
DISALLOWED_TSQUERY_CHARACTERS = /['?\\:]/.freeze
TEXTSEARCH = "(setweight(to_tsvector('simple', accounts.display_name), 'A') || setweight(to_tsvector('simple', accounts.username), 'B') || setweight(to_tsvector('simple', coalesce(accounts.domain, '')), 'C'))"
def readonly_attributes
super - %w(statuses_count following_count followers_count)
end
@ -438,68 +441,68 @@ class Account < ApplicationRecord
end
def search_for(terms, limit = 10, offset = 0)
textsearch, query = generate_query_for_search(terms)
tsquery = generate_query_for_search(terms)
sql = <<-SQL.squish
SELECT
accounts.*,
ts_rank_cd(#{textsearch}, #{query}, 32) AS rank
ts_rank_cd(#{TEXTSEARCH}, to_tsquery('simple', :tsquery), 32) AS rank
FROM accounts
WHERE #{query} @@ #{textsearch}
WHERE to_tsquery('simple', :tsquery) @@ #{TEXTSEARCH}
AND accounts.suspended_at IS NULL
AND accounts.moved_to_account_id IS NULL
ORDER BY rank DESC
LIMIT ? OFFSET ?
LIMIT :limit OFFSET :offset
SQL
records = find_by_sql([sql, limit, offset])
records = find_by_sql([sql, limit: limit, offset: offset, tsquery: tsquery])
ActiveRecord::Associations::Preloader.new.preload(records, :account_stat)
records
end
def advanced_search_for(terms, account, limit = 10, following = false, offset = 0)
textsearch, query = generate_query_for_search(terms)
tsquery = generate_query_for_search(terms)
if following
sql = <<-SQL.squish
WITH first_degree AS (
SELECT target_account_id
FROM follows
WHERE account_id = ?
WHERE account_id = :id
UNION ALL
SELECT ?
SELECT :id
)
SELECT
accounts.*,
(count(f.id) + 1) * ts_rank_cd(#{textsearch}, #{query}, 32) AS rank
(count(f.id) + 1) * ts_rank_cd(#{TEXTSEARCH}, to_tsquery('simple', :tsquery), 32) AS rank
FROM accounts
LEFT OUTER JOIN follows AS f ON (accounts.id = f.account_id AND f.target_account_id = ?)
LEFT OUTER JOIN follows AS f ON (accounts.id = f.account_id AND f.target_account_id = :id)
WHERE accounts.id IN (SELECT * FROM first_degree)
AND #{query} @@ #{textsearch}
AND to_tsquery('simple', :tsquery) @@ #{TEXTSEARCH}
AND accounts.suspended_at IS NULL
AND accounts.moved_to_account_id IS NULL
GROUP BY accounts.id
ORDER BY rank DESC
LIMIT ? OFFSET ?
LIMIT :limit OFFSET :offset
SQL
records = find_by_sql([sql, account.id, account.id, account.id, limit, offset])
records = find_by_sql([sql, id: account.id, limit: limit, offset: offset, tsquery: tsquery])
else
sql = <<-SQL.squish
SELECT
accounts.*,
(count(f.id) + 1) * ts_rank_cd(#{textsearch}, #{query}, 32) AS rank
(count(f.id) + 1) * ts_rank_cd(#{TEXTSEARCH}, to_tsquery('simple', :tsquery), 32) AS rank
FROM accounts
LEFT OUTER JOIN follows AS f ON (accounts.id = f.account_id AND f.target_account_id = ?) OR (accounts.id = f.target_account_id AND f.account_id = ?)
WHERE #{query} @@ #{textsearch}
LEFT OUTER JOIN follows AS f ON (accounts.id = f.account_id AND f.target_account_id = :id) OR (accounts.id = f.target_account_id AND f.account_id = :id)
WHERE to_tsquery('simple', :tsquery) @@ #{TEXTSEARCH}
AND accounts.suspended_at IS NULL
AND accounts.moved_to_account_id IS NULL
GROUP BY accounts.id
ORDER BY rank DESC
LIMIT ? OFFSET ?
LIMIT :limit OFFSET :offset
SQL
records = find_by_sql([sql, account.id, account.id, limit, offset])
records = find_by_sql([sql, id: account.id, limit: limit, offset: offset, tsquery: tsquery])
end
ActiveRecord::Associations::Preloader.new.preload(records, :account_stat)
@ -523,12 +526,13 @@ class Account < ApplicationRecord
private
def generate_query_for_search(terms)
terms = Arel.sql(connection.quote(terms.gsub(/['?\\:]/, ' ')))
textsearch = "(setweight(to_tsvector('simple', accounts.display_name), 'A') || setweight(to_tsvector('simple', accounts.username), 'B') || setweight(to_tsvector('simple', coalesce(accounts.domain, '')), 'C'))"
query = "to_tsquery('simple', ''' ' || #{terms} || ' ''' || ':*')"
def generate_query_for_search(unsanitized_terms)
terms = unsanitized_terms.gsub(DISALLOWED_TSQUERY_CHARACTERS, ' ')
[textsearch, query]
# The final ":*" is for prefix search.
# Not sure what surrounding spaces are for, but they were there in the
# original code.
"' #{terms} ':*"
end
end